This commit is contained in:
TerenceLiu98 2022-11-04 22:47:05 +08:00
parent 6d4d726447
commit 30de2d2269
11 changed files with 1019 additions and 1355 deletions

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@ -1,8 +1,62 @@
{
"cells": [
{
"cell_type": "markdown",
"id": "b705b060",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"# Steepest Descent Method\n",
"\n",
"Instructor: Dr.Yuhui Deng\n",
"\n",
"![level_gradient](figure/level_gradient.png)"
]
},
{
"cell_type": "markdown",
"id": "f576c3bd",
"metadata": {
"slideshow": {
"slide_type": "subslide"
}
},
"source": [
"## Problem Description\n",
"\n",
"Problem: \n",
"\n",
"$\\begin{align*} \n",
"min(fx) \\\\\n",
"s.t. \\ x \\in \\mathbb{R}^n\n",
"\\end{align*}$\n",
"where\n",
"\n",
"* $f: \\mathbb{R}^n \\rightarrow \\mathbb{R}$\n",
"* No constraints are placed on the variables $X$\n"
]
},
{
"cell_type": "markdown",
"id": "c6e94df1",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"# One Dimential Function\n",
"\n",
"$$min \\ f(x)=x^2 - 4x + 7$$\n",
"\n"
]
},
{
"cell_type": "code",
"execution_count": 4,
"execution_count": null,
"id": "af1d5646-4b13-4039-9f76-8042bc9dbda3",
"metadata": {},
"outputs": [],
@ -12,283 +66,132 @@
},
{
"cell_type": "code",
"execution_count": 5,
"execution_count": null,
"id": "8ce3dbbd-a698-448b-a2c6-772286c745d5",
"metadata": {},
"outputs": [
{
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"VBox(children=(HBox(children=(VBox(children=(Text(value='-2 * x * sin(-(pi/4) * x)+10', description='Expressio…"
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{
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"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
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},
"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
}
],
"outputs": [],
"source": [
"gd1 = gd_1d()"
]
},
{
"cell_type": "code",
"execution_count": 6,
"execution_count": null,
"id": "a1765810-6cd8-4e1a-aaa6-7691a7b2a42e",
"metadata": {},
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{
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"VBox(children=(HBox(children=(Dropdown(options=(('(1 - 8 * x1 + 7 * x1**2 - (7/3) * x1**3 + (1/4) * x1**4) * x…"
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"data": {
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"Output()"
]
},
"metadata": {},
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},
{
"data": {
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"Output()"
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"Output()"
]
},
"metadata": {},
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}
],
"outputs": [],
"source": [
"gd2 = gd_2d()"
]
},
{
"cell_type": "code",
"execution_count": 7,
"id": "88e5e47f-3a02-4919-a74e-a4758c56390a",
"execution_count": null,
"id": "06b73a46-f6d5-420d-a668-abaf2c6127a3",
"metadata": {},
"outputs": [],
"source": [
"expr = sympify(gd2.wg_expr.value)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "e7504cf8-514c-444a-bd62-91a13b067cf6",
"metadata": {},
"outputs": [],
"source": [
"expr"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "ff3f9fa9-9071-45c5-a939-d5f0bbe7b37e",
"metadata": {},
"outputs": [],
"source": [
"from sympy import *\n",
"from sympy.abc import x\n",
"expr = \"(x - 2)**2 + 3\"\n",
"ex = sympify(expr)\n",
"solve(ex, x)"
]
},
{
"cell_type": "code",
"execution_count": 1,
"id": "61e0d2b8-41c8-4790-8b25-2df6ba4c3625",
"metadata": {},
"outputs": [],
"source": [
"from optimization.common import *"
]
},
{
"cell_type": "code",
"execution_count": 2,
"id": "cc84e26c-7135-427b-9a5b-c39b6b495fe5",
"metadata": {},
"outputs": [
{
"data": {
"text/latex": [
"$\\displaystyle \\operatorname{Plane}\\left(\\operatorname{Point3D}\\left(1, 1, 1\\right), \\left( 1, \\ 4, \\ 7\\right)\\right)$"
],
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"text/plain": [
"Plane(Point3D(1, 1, 1), (1, 4, 7))"
"VBox(children=(HBox(children=(Text(value='-2 * x * sin(-(pi/4) * x)+10', description='Expression:', style=Text…"
]
},
"execution_count": 7,
"metadata": {},
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"output_type": "display_data"
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"text/plain": [
"Output()"
]
},
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"version_minor": 0
},
"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
}
],
"source": [
"from sympy import Plane, Point3D\n",
"Plane(Point3D(1, 1, 1), Point3D(2, 3, 4), Point3D(2, 2, 2))\n",
"Plane((1, 1, 1), (2, 3, 4), (2, 2, 2))\n",
"Plane(Point3D(1, 1, 1), normal_vector=(1,4,7))"
"a = func_1d()"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "b0563398-5a79-47aa-9c31-474a518daa0d",
"metadata": {},
"outputs": [],
"source": [
"from sympy import Point3D, Plane\n",
"a = Plane(Point3D(1, 1, 1), Point3D(2, 3, 4), Point3D(2, 2, 2))\n",
"a.normal_vector\n",
"a = Plane(Point3D(1, 1, 1), normal_vector=(1, 4, 7))\n",
"a.normal_vector"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "cf7ed01e-f42a-4a3d-8c2f-e0e7dfa682c5",
"metadata": {},
"outputs": [],
"source": [
"from sympy.vector import CoordSys3D, gradient\n",
"from sympy import symbols, sympify, lambdify, diff\n",
"expr = sympify(\"(1 - 8 * x1 + 7 * x1**2 - (7/3) * x1**3 + (1/4) * x1**4) * x2**2 * E**(-x2)\")\n",
"x1, x2 = symbols(\"x1\"), symbols(\"x2\")\n",
"gradient(expr)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "bdbceb9a-42f0-42e3-a2cb-573b4d82e4af",
"metadata": {},
"outputs": [],
"source": [
"from sympy.vector import CoordSys3D\n",
"R = CoordSys3D('R')\n",
"v = (1 - 8*R.x +7*R.x**2 - (7/3)*R.x**3 + (1/4 * R.x**4) * R.y**2 * np.exp(1)**(-R.y))"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "af76a657-c281-41b4-83c3-c3f73376d948",
"metadata": {},
"outputs": [],
"source": [
"from sympy.vector import CoordSys3D, Del\n",
"R = CoordSys3D('R')\n",
"delop = Del()\n",
"gradient_field = delop((1 - 8*R.x +7*R.x**2 - (7/3)*R.x**3 + (1/4 * R.x**4) * R.y**2 * np.exp(1)**(-R.y)))\n",
"gradient_field"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "d987886f-1231-487a-88dc-47e8a45d728c",
"metadata": {},
"outputs": [],
"source": [
"import sympy\n",
"\n",
"#define symbolic vars, function\n",
"x,y=sympy.symbols('x y')\n",
"fun= sympify(\"(1 - 8 * x + 7 * x**2 - (7/3) * x**3 + (1/4) * x**4) * y**2 * E**(-y)\")\n",
"#fun=3*x**2-5*y**2\n",
"#take the gradient symbolically\n",
"gradfun=[sympy.diff(fun,var) for var in (x1,x2)]\n",
"numgradfun=sympy.lambdify([x,y],gradfun)\n",
"graddat=numgradfun(xx1_o,xx2_o)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "da34c7be-025f-4326-8138-9e78e2043b7e",
"metadata": {},
"outputs": [],
"source": [
"import numpy as np\n",
"import plotly.figure_factory as ff\n",
"import math\n",
"\n",
"X,Y=np.meshgrid(np.arange(0,5, 0.25),np.arange(0,5, 0.25))\n",
"graddat=numgradfun(X,Y)\n",
"\n",
"\n",
"fig = ff.create_quiver(X, Y, graddat[0], graddat[1],scale=.05, arrow_scale=.1, angle=math.pi/6)\n",
"fig.update_traces(line_color=\"red\")\n",
"fig.update_layout(height=800)\n",
"fig.show()"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "62504d86-9dc8-42b2-b052-d7acfe8be5e0",
"metadata": {},
"outputs": [],
"source": [
"fig.data[0][\"x\"]"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "415a2abd-3ea4-48ee-9923-c9897105ad27",
"metadata": {},
"outputs": [],
"source": [
"import numpy as np\n",
"import matplotlib.pyplot as plt\n",
"\n",
"X,Y=np.meshgrid(np.arange(0,5, 0.1),np.arange(0,5,0.1))\n",
"graddat=numgradfun(X,Y)\n",
"\n",
"plt.figure()\n",
"plt.quiver(X,Y,graddat[0],graddat[1])\n",
"plt.show()"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "2c60be92-8c74-4f46-b7fc-bb9d7150cbe0",
"id": "98061d97-555e-486a-a07d-1b8c37cd2471",
"metadata": {},
"outputs": [],
"source": []
}
],
"metadata": {
"celltoolbar": "Slideshow",
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"display_name": "Python 3 (ipykernel)",
"language": "python",

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{
"cells": [
{
"cell_type": "markdown",
"id": "b705b060",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"# Steepest Descent Method\n",
"\n",
"Instructor: Dr.Yuhui Deng\n",
"\n",
"![level_gradient](figure/level_gradient.png)"
]
},
{
"cell_type": "markdown",
"id": "f576c3bd",
"metadata": {
"slideshow": {
"slide_type": "subslide"
}
},
"source": [
"## Problem Description\n",
"\n",
"Problem: \n",
"\n",
"$\\begin{align*} \n",
"min(fx) \\\\\n",
"s.t. \\ x \\in \\mathbb{R}^n\n",
"\\end{align*}$\n",
"where\n",
"\n",
"* $f: \\mathbb{R}^n \\rightarrow \\mathbb{R}$\n",
"* No constraints are placed on the variables $X$\n"
]
},
{
"cell_type": "markdown",
"id": "c6e94df1",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"# One Dimential Function\n",
"\n",
"$$min \\ f(x)=x^2 - 4x + 7$$\n",
"\n"
]
},
{
"cell_type": "code",
"execution_count": 1,
"execution_count": null,
"id": "af1d5646-4b13-4039-9f76-8042bc9dbda3",
"metadata": {},
"outputs": [],
@ -12,120 +66,20 @@
},
{
"cell_type": "code",
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"execution_count": null,
"id": "8ce3dbbd-a698-448b-a2c6-772286c745d5",
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{
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"VBox(children=(HBox(children=(VBox(children=(Text(value='-2 * x * sin(-(pi/4) * x)+10', description='Expressio…"
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},
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"Output()"
]
},
"metadata": {},
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},
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"version_minor": 0
},
"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
}
],
"outputs": [],
"source": [
"gd1 = gd_1d()"
]
},
{
"cell_type": "code",
"execution_count": 3,
"execution_count": null,
"id": "a1765810-6cd8-4e1a-aaa6-7691a7b2a42e",
"metadata": {},
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{
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"VBox(children=(HBox(children=(Dropdown(options=(('(1 - 8 * x1 + 7 * x1**2 - (7/3) * x1**3 + (1/4) * x1**4) * x…"
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},
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{
"data": {
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"version_minor": 0
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"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"application/vnd.jupyter.widget-view+json": {
"model_id": "17c95b2c789044439b3e4412a41cdff4",
"version_major": 2,
"version_minor": 0
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"text/plain": [
"Output()"
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},
"metadata": {},
"output_type": "display_data"
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{
"data": {
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"version_minor": 0
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"text/plain": [
"Output()"
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},
"metadata": {},
"output_type": "display_data"
}
],
"outputs": [],
"source": [
"gd2 = gd_2d()"
]
@ -133,13 +87,111 @@
{
"cell_type": "code",
"execution_count": null,
"id": "48944e3c-932a-4733-b77d-a2b50cee2e5a",
"id": "06b73a46-f6d5-420d-a668-abaf2c6127a3",
"metadata": {},
"outputs": [],
"source": [
"expr = sympify(gd2.wg_expr.value)"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "e7504cf8-514c-444a-bd62-91a13b067cf6",
"metadata": {},
"outputs": [],
"source": [
"expr"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "ff3f9fa9-9071-45c5-a939-d5f0bbe7b37e",
"metadata": {},
"outputs": [],
"source": [
"from sympy import *\n",
"from sympy.abc import x\n",
"expr = \"(x - 2)**2 + 3\"\n",
"ex = sympify(expr)\n",
"solve(ex, x)"
]
},
{
"cell_type": "code",
"execution_count": 1,
"id": "61e0d2b8-41c8-4790-8b25-2df6ba4c3625",
"metadata": {},
"outputs": [],
"source": [
"from optimization.common import *"
]
},
{
"cell_type": "code",
"execution_count": 2,
"id": "cc84e26c-7135-427b-9a5b-c39b6b495fe5",
"metadata": {},
"outputs": [
{
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"version_minor": 0
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"text/plain": [
"VBox(children=(HBox(children=(Text(value='-2 * x * sin(-(pi/4) * x)+10', description='Expression:', style=Text…"
]
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"metadata": {},
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"Output()"
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},
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"version_minor": 0
},
"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
}
],
"source": [
"a = func_1d()"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "98061d97-555e-486a-a07d-1b8c37cd2471",
"metadata": {},
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"source": []
}
],
"metadata": {
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"display_name": "Python 3 (ipykernel)",
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algorithm/lecture.ipynb Normal file
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{
"cells": [
{
"cell_type": "markdown",
"id": "9b492ee6",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"# Steepest Descent Method\n",
"\n",
"Instructor: Dr.Yuhui Deng"
]
},
{
"cell_type": "code",
"execution_count": 6,
"id": "2472b8ca",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"outputs": [
{
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"version_minor": 0
},
"text/plain": [
"VBox(children=(HBox(children=(Text(value='x1^2 + x2^2', description='Expression:', style=TextStyle(description…"
]
},
"metadata": {},
"output_type": "display_data"
},
{
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"version_minor": 0
},
"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"text/plain": [
"<optimization.common.contourPlot2d at 0x147a89a30>"
]
},
"execution_count": 6,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"from optimization.common import *\n",
"contourPlot2d(environ=\"notebook\")"
]
},
{
"cell_type": "markdown",
"id": "1d34025b",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"## Problem Description\n",
"\n",
"$\\textbf{Problem:}\\left\\{\\begin{align*}\n",
"\\min \\ f(x) \\\\\n",
"s.t. \\ x \\in \\mathbb{R}^n\n",
"\\end{align*} \\right.$\n",
"\n",
"where: \n",
"* $f: \\mathbb{R}^n \\mapsto \\mathbb{R}$\n",
"* No constraints are placed on the variables $x$"
]
},
{
"cell_type": "markdown",
"id": "6f867a65",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"### One Dimentional Function\n",
"\n",
"$$\\min \\ f(x) = x^2 - 4x + 7$$"
]
},
{
"cell_type": "code",
"execution_count": 8,
"id": "302d9c60",
"metadata": {
"slideshow": {
"slide_type": "fragment"
}
},
"outputs": [
{
"data": {
"application/vnd.jupyter.widget-view+json": {
"model_id": "cf33688620c54a4d85cb0f9dbce63fe3",
"version_major": 2,
"version_minor": 0
},
"text/plain": [
"VBox(children=(HBox(children=(Text(value='(x - 2)**2 + 3', description='Expression:', style=TextStyle(descript…"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"application/vnd.jupyter.widget-view+json": {
"model_id": "aa0a66db4d33470fbe7a091588bb27a6",
"version_major": 2,
"version_minor": 0
},
"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"application/vnd.jupyter.widget-view+json": {
"model_id": "3a84ef2c3bd14854b81d4cb48005991f",
"version_major": 2,
"version_minor": 0
},
"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"text/plain": [
"<optimization.common.funcPlot1d at 0x1674d2eb0>"
]
},
"execution_count": 8,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"funcPlot1d(environ=\"notebook\")"
]
},
{
"cell_type": "markdown",
"id": "e2ce7e95",
"metadata": {
"slideshow": {
"slide_type": "fragment"
}
},
"source": [
"$$x_{k+1} = x_{k} + a \\cdot d \\quad d = \\left\\{\\begin{align*} +1 &\\text{ left} \\\\ -1 &\\text{ right}\\end{align*}\\right. \\ a \\geq 0$$"
]
},
{
"cell_type": "code",
"execution_count": 10,
"id": "a4827f0c",
"metadata": {},
"outputs": [
{
"data": {
"application/vnd.jupyter.widget-view+json": {
"model_id": "578d548bc16c45caa29f47f60b58acf0",
"version_major": 2,
"version_minor": 0
},
"text/plain": [
"VBox(children=(HBox(children=(VBox(children=(Text(value='sin(x) + sin((10.0 / 3.0) * x)', description='Express…"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"application/vnd.jupyter.widget-view+json": {
"model_id": "ead520028b844ef78e0932d537ac7172",
"version_major": 2,
"version_minor": 0
},
"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"application/vnd.jupyter.widget-view+json": {
"model_id": "16060b8b5ae04f31833395b3b1f4259c",
"version_major": 2,
"version_minor": 0
},
"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"text/plain": [
"<optimization.gd_new.gd_1d at 0x1675023a0>"
]
},
"execution_count": 10,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"gd_1d(environ=\"notebook\")"
]
},
{
"cell_type": "markdown",
"id": "f55e58dd",
"metadata": {
"slideshow": {
"slide_type": "slide"
}
},
"source": [
"### Multi Dimentional Function\n",
"\n",
"$$(1 - 8 \\cdot x_1 + 7 \\cdot x_1^2 - \\frac{7x_{1}^{3}}{3} + \\frac{x^{4}}{4}) \\cdot x_2^2 \\cdot e^{(-x_2)}$$"
]
},
{
"cell_type": "code",
"execution_count": 11,
"id": "7c589589",
"metadata": {
"slideshow": {
"slide_type": "fragment"
}
},
"outputs": [
{
"data": {
"application/vnd.jupyter.widget-view+json": {
"model_id": "5d9c8974d7c04f4dbdb7aa333ae7d172",
"version_major": 2,
"version_minor": 0
},
"text/plain": [
"VBox(children=(HBox(children=(Text(value='(1 - 8 * x1 + 7 * x1^2 - (7/3) * x1^3 + (1/4) * x1^4) * x2^2 * E^(-x…"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"application/vnd.jupyter.widget-view+json": {
"model_id": "909764ee6cd94053a17da64592bb11e5",
"version_major": 2,
"version_minor": 0
},
"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"application/vnd.jupyter.widget-view+json": {
"model_id": "ba448ff14b8f454b8f4b6d3cb8f92c9e",
"version_major": 2,
"version_minor": 0
},
"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"text/plain": [
"<optimization.common.funcPlot2d at 0x167583b50>"
]
},
"execution_count": 11,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"funcPlot2d(environ=\"notebook\")"
]
},
{
"cell_type": "markdown",
"id": "1a5b2203",
"metadata": {
"slideshow": {
"slide_type": "subslide"
}
},
"source": [
"Some Questions:\n",
"\n",
"1. How many choices for the searching direction?\n",
"2. Which direction will you choose?\n",
"3. How far will you walk?\n"
]
},
{
"cell_type": "code",
"execution_count": 13,
"id": "f28bd167",
"metadata": {
"slideshow": {
"slide_type": "subslide"
}
},
"outputs": [
{
"data": {
"application/vnd.jupyter.widget-view+json": {
"model_id": "bd08d4c9d0014062a1e0654177dfbd55",
"version_major": 2,
"version_minor": 0
},
"text/plain": [
"VBox(children=(HBox(children=(Dropdown(options=(('(1 - 8 * x1 + 7 * x1**2 - (7/3) * x1**3 + (1/4) * x1**4) * x…"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"application/vnd.jupyter.widget-view+json": {
"model_id": "26123777d5214fa28d4bfd16d9afe3b8",
"version_major": 2,
"version_minor": 0
},
"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"application/vnd.jupyter.widget-view+json": {
"model_id": "176568fccd1f49d79abc66fff51859d6",
"version_major": 2,
"version_minor": 0
},
"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"application/vnd.jupyter.widget-view+json": {
"model_id": "7f1d7ace2eef4a5480c72444f52fd4c1",
"version_major": 2,
"version_minor": 0
},
"text/plain": [
"Output()"
]
},
"metadata": {},
"output_type": "display_data"
},
{
"data": {
"text/plain": [
"<optimization.gd_new.gd_2d at 0x167c26b20>"
]
},
"execution_count": 13,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"gd_2d(environ=\"notebook\")"
]
},
{
"cell_type": "markdown",
"id": "d585d6de",
"metadata": {
"slideshow": {
"slide_type": "subslide"
}
},
"source": [
"### Multi Dimentional Function\n",
"\n",
"**Descent Direction** If a direction vector $d$ has the property that at least for sufficiently small $\\alpha > 0$, \n",
"$$f(x + \\alpha d) < f(x)$$\n",
"then $d$ is said a **descent direction** for function $f$ at point $x$."
]
},
{
"cell_type": "markdown",
"id": "3adf3a40",
"metadata": {
"slideshow": {
"slide_type": "subslide"
}
},
"source": [
"### Multi Dimentional Function\n",
"\n",
"梯度取极值"
]
},
{
"cell_type": "markdown",
"id": "49f800ef",
"metadata": {},
"source": [
"### Multi Dimentional Function\n",
"\n",
"**When exact line search is used**, the steepest descent method obtains\n",
"$$x^{k+1} = x^{k} - \\alpha_{k} \\nabla f(x^k)$$\n",
"where $\\alpha_k$ is the solution of the one-dimensional minimization problem: \n",
"$$\\min_{\\alpha > 0} F(\\alpha) \\equiv f(x^{k} - \\alpha \\nabla f(x^k))$$\n",
"So,\n",
"$$\\begin{align*}F^{\\prime} = 0 \\Rightarrow - \\nabla f(x^k - \\alpha_k \\nabla f(x^k))^T \\nabla f(x^k) = 0 \\\\\n",
"\\Rightarrow \\nabla f(x^{k+1})^T \\nabla f(x^k) = 0\n",
"\\end{align*}$$\n",
"\n",
"This means that **every pair of $\\nabla f(x^{k+1})$ and $\\nabla f(x^k)$ are vertical.** Hence $\\{x^k\\}$ usually takes a zigzag path to approach the solution $x^{*}$. By this fact, we may better understand the reason why steepest descent method progresses slowly when the contours of $f$ are flat, see Section 4.7 (Appendix 2)."
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "1b5fb35c",
"metadata": {},
"outputs": [],
"source": []
}
],
"metadata": {
"celltoolbar": "Slideshow",
"kernelspec": {
"display_name": "Python 3 (ipykernel)",
"language": "python",
"name": "python3"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 3
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
"version": "3.9.13"
}
},
"nbformat": 4,
"nbformat_minor": 5
}

View File

@ -1,138 +0,0 @@
import copy
import time
import sympy
import numpy as np
from scipy.misc import derivative
from sympy import symbols, sympify, lambdify, diff
import ipywidgets as widgets
from IPython.display import display, clear_output
from tqdm import tqdm
import matplotlib.pyplot as plt
import plotly.graph_objects as go
import plotly.io as pio
import warnings
warnings.filterwarnings("ignore")
class gradient_descent_2d(object):
def __init__(self, environ:str="jupyterlab"):
pio.renderers.default = environ # 'notebook' or 'colab' or 'jupyterlab'
self.wg_expr = widgets.Dropdown(options=[("(sin(x1) - 2) + (sin(x2) - 2) ** 2", "(sin(x1) - 2) + (sin(x2) - 2) ** 2"),
("(sin(x1) - 2) ** (1/2) + (sin(x2) - 2) ** 2", "(sin(x1) - 2) ** (1/2) + (sin(x2) - 2) ** 2"),
("(sin(x1) - 2) ** 2 + (sin(x2) - 2) ** 2", "(sin(x1) - 2) ** 2 + (sin(x2) - 2) ** 2")],
value="(sin(x1) - 2) ** 2 + (sin(x2) - 2) ** 2", descrption="Expression")
self.wg_x0 = widgets.Text(value="5,5",
description="Startpoint:")
self.wg_lr = widgets.FloatText(value="1e-1",
description="step size:")
self.wg_epsilon = widgets.FloatText(value="1e-5",
description="criterion:")
self.wg_max_iter = widgets.IntText(value="1000",
description="max iteration")
self.button_compute = widgets.Button(description="Compute")
self.button_plot = widgets.Button(description="Plot")
self.compute_output = widgets.Output()
self.plot_output = widgets.Output()
self.params_lvbox = widgets.VBox([self.wg_x0, self.wg_lr])
self.params_rvbox = widgets.VBox([self.wg_epsilon, self.wg_max_iter])
self.exp_box = widgets.HBox([self.wg_expr])
self.params_box = widgets.HBox([self.params_lvbox, self.params_rvbox], description="Parameters")
self.button_box = widgets.HBox([self.button_compute, self.button_plot], description="operations")
self.config = widgets.VBox([self.exp_box, self.params_box, self.button_box])
self.initialization()
def initialization(self):
display(self.config)
self.button_compute.on_click(self.compute)
display(self.compute_output)
self.button_plot.on_click(self.plot)
display(self.plot_output)
def compute(self, *args):
with self.compute_output:
x0 = np.array(self.wg_x0.value.split(","), dtype=float)
xn = x0
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
self.xn_list, self.df_list = [], []
for n in tqdm(range(0, self.wg_max_iter.value)):
gradient = np.array([diff(expr, x1).subs(x1, xn[0]).subs(x2, xn[1]),
diff(expr, x2).subs(x1, xn[0]).subs(x2, xn[1])], dtype=float)
self.xn_list.append(xn)
self.df_list.append(gradient)
if np.linalg.norm(gradient, ord=2) < self.wg_epsilon.value:
clear_output(wait=True)
print("Found solution of {} after".format(expr), n, "iterations")
print("x* = [{}, {}]".format(xn[0], xn[1]))
return None
xn = xn - self.wg_lr.value * gradient
clear_output(wait=True)
display("Exceeded maximum iterations. No solution found.")
return None
def plot(self, *args):
with self.plot_output:
clear_output(wait=True)
x0 = np.array(self.wg_x0.value.split(","), dtype=float)
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
xx1 = np.arange(np.array(self.xn_list)[:, 0].min() * 0.5, np.array(self.xn_list)[:, 0].max() * 1.5, 0.1)
xx2 = np.arange(np.array(self.xn_list)[:, 1].min() * 0.5, np.array(self.xn_list)[:, 1].max() * 1.5, 0.1)
xx1_tangent = np.arange(np.array(self.xn_list)[:, 0].min(), np.array(self.xn_list)[:, 0].max(), 0.1)
xx2_tangent = np.arange(np.array(self.xn_list)[:, 1].min(), np.array(self.xn_list)[:, 1].max(), 0.1)
xx1_o, xx2_o = xx1, xx2
xx1, xx2 = np.meshgrid(xx1, xx2)
xx1_tangent, xx2_tangent = np.meshgrid(xx1_tangent, xx2_tangent)
f = lambdify((x1, x2), expr, "numpy")
fx = f(xx1, xx2)
f_xn = f(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1])
partial_x1 = lambdify((x1, x2), diff(expr, x1), "numpy")
partial_x2 = lambdify((x1, x2), diff(expr, x2), "numpy")
plane = partial_x1(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1]) * (x1 - np.array(self.xn_list)[:, 0]) + partial_x2(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1]) * (x2 - np.array(self.xn_list)[:, 1]) + f_xn
z = [lambdify((x1, x2), plane[i], "numpy")(xx1_tangent, xx2_tangent) for i in range(0, len(plane))]
frames, steps = [], []
for k in range(len(f_xn)):
tmp_trace1 = go.Scatter3d(x=np.array(self.xn_list)[:k,0], y=np.array(self.xn_list)[:k,1], z=f_xn)
tmp_trace2 = go.Surface(x=xx1_tangent, y=xx2_tangent, z=z[k], showscale=True, opacity=0.5)
frame = go.Frame(dict(data=[tmp_trace1, tmp_trace2], name=f'frame{k+1}'), traces=[1, 2])
frames.append(frame)
step = dict(
method="update",
args=[{"visible": [True]},
{"title": "Slider switched to step: " + str(k+1)}], # layout attribute
)
steps.append(step)
sliders = [dict(steps= [dict(method= 'animate',
args= [[f'frame{k+1}'],
dict(mode= 'immediate',
frame= dict( duration=0, redraw= True ),
transition=dict( duration=0)
)
],
#label='Date : {}'.format(date_range[k])
) for k in range(0,len(frames))],
transition= dict(duration=0),
x=0,
y=0,
currentvalue=dict(font=dict(size=12), visible=True, xanchor= 'center'),
len=1.0)
]
trace1 = go.Surface(x=xx1, y=xx2, z=fx, showscale=False, opacity=0.6)
trace2 = go.Scatter3d(x=None, y=None, z=None)
fig = go.Figure(data=[trace1, trace2], frames=frames)
fig.update_layout(updatemenus=[dict(type="buttons", buttons=[dict(label="Play", method="animate", args=[None, dict(fromcurrent=True)]), \
dict(label="Pause", method="animate", args=[[None], \
dict(fromcurrent=True, mode='immediate', transition= {'duration': 0}, frame=dict(redraw=True, duration=0))])])],
margin=dict(r=20, l=10, b=10, t=10), sliders=sliders)
fig.show()

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@ -0,0 +1,188 @@
import math
import copy
import time
import sympy
import numpy as np
from scipy.misc import derivative
from sympy import symbols, sympify, lambdify, diff, solve
import ipywidgets as widgets
from IPython.display import Image, display, clear_output
from tqdm import tqdm
import matplotlib.pyplot as plt
import plotly.io as pio
import plotly.graph_objects as go
import plotly.figure_factory as ff
class funcPlot1d(object):
def __init__(self, environ:str="jupyterlab"):
pio.renderers.default = environ # 'notebook' or 'colab' or 'jupyterlab'
self.wg_expr = widgets.Text(value="(x - 2)**2 + 3",
description="Expression:",
style={'description_width': 'initial'})
self.wg_x_range = widgets.Text(value="-10,10",
description="X-axis range",
style={"description_width": "initial"})
self.button_compute = widgets.Button(description="Compute")
self.button_plot = widgets.Button(description="Plot")
self.compute_output = widgets.Output()
self.plot_output = widgets.Output()
self.params_box = widgets.HBox([self.wg_expr, self.wg_x_range])
self.button_box = widgets.HBox([self.button_compute, self.button_plot], description="operations")
self.config = widgets.VBox([self.params_box, self.button_box])
self.initialization()
def initialization(self):
display(self.config)
self.button_compute.on_click(self.compute)
display(self.compute_output)
self.button_plot.on_click(self.plot)
display(self.plot_output)
def compute(self, *args):
with self.compute_output:
x = symbols("x")
expr = sympify(self.wg_expr.value)
f = lambdify(x, expr)
clear_output(wait=True)
print(solve(expr, x))
def plot(self, *args):
with self.plot_output:
fig = go.Figure()
x_range = np.array(self.wg_x_range.value.split(","), dtype=float)
x_num = np.arange(x_range[0], x_range[1], 0.1)
expr = sympify(self.wg_expr.value)
x = symbols("x")
f = lambdify(x, expr)
fx = f(x_num)
fig.add_scatter(x=x_num, y=fx)
clear_output(wait=True)
fig.show()
class funcPlot2d(object):
def __init__(self, environ:str="jupyterlab", type="default"):
if type == "default":
self.initialization_default(environ=environ)
self.user_step = 1
elif type == "custom":
self.initlization_custom()
self.compute_custom()
else:
return None
def initialization_default(self, environ):
pio.renderers.default = environ # 'notebook' or 'colab' or 'jupyterlab'
self.wg_expr = widgets.Text(value="(1 - 8 * x1 + 7 * x1^2 - (7/3) * x1^3 + (1/4) * x1^4) * x2^2 * E^(-x2)",
description="Expression:",
style={'description_width': 'initial'})
self.button_plot_default = widgets.Button(description="3D Plot")
self.compute_output = widgets.Output()
self.plot_default_output = widgets.Output()
self.plot_contour_output = widgets.Output()
self.exp_box = widgets.HBox([self.wg_expr])
self.button_box = widgets.HBox([self.button_plot_default], description="operations")
self.config = widgets.VBox([self.exp_box, self.button_box])
display(self.config)
display(self.compute_output)
self.button_plot_default.on_click(self.plot_default)
img1 = self.plot_default_output
display(img1)
def plot_default(self, *args):
with self.plot_default_output:
clear_output(wait=True)
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
xx1 = np.arange(0, 5, 0.25)
xx2 = np.arange(0, 5, 0.25)
xx1_o, xx2_o = xx1, xx2
xx1, xx2 = np.meshgrid(xx1, xx2)
xx1_tangent, xx2_tangent = np.meshgrid(xx1_o, xx2_o)
#xx1_tangent, xx2_tangent = array_mesh(np.arange(0, 5, 0.25), 10), array_mesh(np.arange(0, 5, 0.25), 10)
f = lambdify((x1, x2), expr, "numpy")
fx = f(xx1, xx2)
## projection
z_offset = (np.min(fx)) * np.ones(fx.shape)
proj_z = lambda x, y, z: z
colorsurfz = proj_z(xx1, xx2, fx)
from plotly.subplots import make_subplots
fig = make_subplots(rows=1, cols=1, specs=[[{'type': 'surface'}]])
fig.add_trace(go.Surface(contours = {"x": {"show": True}, "y":{"show": True}, "z":{"show": True}}, x=xx1, y=xx2, z=fx), row=1, col=1)
fig.add_trace(go.Scatter3d(x=None, y=None, z=None), row=1, col=1)
fig.add_trace(go.Surface(x=None, y=None, z=None, showlegend=False, showscale=False, colorscale='Blues'), row=1, col=1)
frames = [go.Frame(data=[go.Surface(visible=True, showscale=False, opacity=0.8)],
traces=[0])]
fig.frames = frames
self.fig_frames = frames
fig.update_layout(height=600, scene_aspectmode='manual', scene_aspectratio=dict(x=0, y=0, z=0), updatemenus=[dict(type="buttons")])
fig.update_scenes(xaxis_visible=False,
yaxis_visible=False,
zaxis_visible=False)
fig.update_scenes(camera_projection_type = "orthographic")
fig.show()
class contourPlot2d(object):
def __init__(self, environ:str="jupyterlab"):
pio.renderers.default = environ # 'notebook' or 'colab' or 'jupyterlab'
self.wg_expr = widgets.Text(value="x1^2 + x2^2",
description="Expression:",
style={'description_width': 'initial'})
self.button_plot = widgets.Button(description="Plot")
self.plot_output = widgets.Output()
self.params_box = widgets.HBox([self.wg_expr])
self.button_box = widgets.HBox([self.button_plot], description="operations")
self.config = widgets.VBox([self.params_box, self.button_box])
self.initialization()
def initialization(self):
display(self.config)
self.button_plot.on_click(self.plot)
display(self.plot_output)
def plot(self, *args):
with self.plot_output:
clear_output(wait=True)
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
xx1 = np.arange(-5, 5, 0.5)
xx2 = np.arange(-5, 5, 0.5)
xx1_o, xx2_o = xx1, xx2 #np.arange(-5, 5, 0.5), np.arange(-5, 5, 0.5)
xx1, xx2 = np.meshgrid(xx1, xx2)
f = lambdify((x1, x2), expr, "numpy")
fx = f(xx1, xx2)
partial_x1 = lambdify((x1, x2), diff(expr, x1), "numpy")
partial_x2 = lambdify((x1, x2), diff(expr, x2), "numpy")
gradfun=[sympy.diff(expr,var) for var in (x1,x2)]
numgradfun=sympy.lambdify([x1,x2], gradfun)
x1_mesh, x2_mesh = np.meshgrid(xx1_o, xx2_o)
graddat=numgradfun(x1_mesh, x2_mesh)
vec_field = ff.create_quiver(x1_mesh, x2_mesh, graddat[0], graddat[1], scale=.05, arrow_scale=.1, angle=math.pi/4)
vec_field.update_traces(line_color="black")
fig = go.Figure()
fig.add_trace(go.Contour(x=xx1_o, y=xx2_o, z=fx))
for d in vec_field.data:
fig.add_trace(go.Scatter(visible=False, x=d['x'], y=d['y'], line_color="black"))
fig.update_layout(
updatemenus=[dict(type = "buttons",direction = "left",
buttons=list([
dict(args=[{"visible":["True", "True"]}], label="Gradient", method="update")]))], height=800)
fig.show()

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@ -1,138 +0,0 @@
import copy
import time
import sympy
import numpy as np
from scipy.misc import derivative
from sympy import symbols, sympify, lambdify, diff
import ipywidgets as widgets
from IPython.display import display, clear_output
from tqdm import tqdm
import matplotlib.pyplot as plt
import plotly.graph_objects as go
import plotly.io as pio
import warnings
warnings.filterwarnings("ignore")
class gradient_descent_2d(object):
def __init__(self, environ:str="jupyterlab"):
pio.renderers.default = environ # 'notebook' or 'colab' or 'jupyterlab'
self.wg_expr = widgets.Dropdown(options=[("(sin(x1) - 2) + (sin(x2) - 2) ** 2", "(sin(x1) - 2) + (sin(x2) - 2) ** 2"),
("(sin(x1) - 2) ** (1/2) + (sin(x2) - 2) ** 2", "(sin(x1) - 2) ** (1/2) + (sin(x2) - 2) ** 2"),
("(sin(x1) - 2) ** 2 + (sin(x2) - 2) ** 2", "(sin(x1) - 2) ** 2 + (sin(x2) - 2) ** 2")],
value="(sin(x1) - 2) ** 2 + (sin(x2) - 2) ** 2", descrption="Expression")
self.wg_x0 = widgets.Text(value="5,5",
description="Startpoint:")
self.wg_lr = widgets.FloatText(value="1e-1",
description="step size:")
self.wg_epsilon = widgets.FloatText(value="1e-5",
description="criterion:")
self.wg_max_iter = widgets.IntText(value="1000",
description="max iteration")
self.button_compute = widgets.Button(description="Compute")
self.button_plot = widgets.Button(description="Plot")
self.compute_output = widgets.Output()
self.plot_output = widgets.Output()
self.params_lvbox = widgets.VBox([self.wg_x0, self.wg_lr])
self.params_rvbox = widgets.VBox([self.wg_epsilon, self.wg_max_iter])
self.exp_box = widgets.HBox([self.wg_expr])
self.params_box = widgets.HBox([self.params_lvbox, self.params_rvbox], description="Parameters")
self.button_box = widgets.HBox([self.button_compute, self.button_plot], description="operations")
self.config = widgets.VBox([self.exp_box, self.params_box, self.button_box])
self.initialization()
def initialization(self):
display(self.config)
self.button_compute.on_click(self.compute)
display(self.compute_output)
self.button_plot.on_click(self.plot)
display(self.plot_output)
def compute(self, *args):
with self.compute_output:
x0 = np.array(self.wg_x0.value.split(","), dtype=float)
xn = x0
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
self.xn_list, self.df_list = [], []
for n in tqdm(range(0, self.wg_max_iter.value)):
gradient = np.array([diff(expr, x1).subs(x1, xn[0]).subs(x2, xn[1]),
diff(expr, x2).subs(x1, xn[0]).subs(x2, xn[1])], dtype=float)
self.xn_list.append(xn)
self.df_list.append(gradient)
if np.linalg.norm(gradient, ord=2) < self.wg_epsilon.value:
clear_output(wait=True)
print("Found solution of {} after".format(expr), n, "iterations")
print("x* = [{}, {}]".format(xn[0], xn[1]))
return None
xn = xn - self.wg_lr.value * gradient
clear_output(wait=True)
display("Exceeded maximum iterations. No solution found.")
return None
def plot(self, *args):
with self.plot_output:
clear_output(wait=True)
x0 = np.array(self.wg_x0.value.split(","), dtype=float)
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
xx1 = np.arange(np.array(self.xn_list)[:, 0].min() * 0.5, np.array(self.xn_list)[:, 0].max() * 1.5, 0.1)
xx2 = np.arange(np.array(self.xn_list)[:, 1].min() * 0.5, np.array(self.xn_list)[:, 1].max() * 1.5, 0.1)
xx1_tangent = np.arange(np.array(self.xn_list)[:, 0].min(), np.array(self.xn_list)[:, 0].max(), 0.1)
xx2_tangent = np.arange(np.array(self.xn_list)[:, 1].min(), np.array(self.xn_list)[:, 1].max(), 0.1)
xx1_o, xx2_o = xx1, xx2
xx1, xx2 = np.meshgrid(xx1, xx2)
xx1_tangent, xx2_tangent = np.meshgrid(xx1_tangent, xx2_tangent)
f = lambdify((x1, x2), expr, "numpy")
fx = f(xx1, xx2)
f_xn = f(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1])
partial_x1 = lambdify((x1, x2), diff(expr, x1), "numpy")
partial_x2 = lambdify((x1, x2), diff(expr, x2), "numpy")
plane = partial_x1(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1]) * (x1 - np.array(self.xn_list)[:, 0]) + partial_x2(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1]) * (x2 - np.array(self.xn_list)[:, 1]) + f_xn
z = [lambdify((x1, x2), plane[i], "numpy")(xx1_tangent, xx2_tangent) for i in range(0, len(plane))]
frames, steps = [], []
for k in range(len(f_xn)):
tmp_trace1 = go.Scatter3d(x=np.array(self.xn_list)[:k,0], y=np.array(self.xn_list)[:k,1], z=f_xn)
tmp_trace2 = go.Surface(x=xx1_tangent, y=xx2_tangent, z=z[k], showscale=True, opacity=0.5)
frame = go.Frame(dict(data=[tmp_trace1, tmp_trace2], name=f'frame{k+1}'), traces=[1, 2])
frames.append(frame)
step = dict(
method="update",
args=[{"visible": [True]},
{"title": "Slider switched to step: " + str(k+1)}], # layout attribute
)
steps.append(step)
sliders = [dict(steps= [dict(method= 'animate',
args= [[f'frame{k+1}'],
dict(mode= 'immediate',
frame= dict( duration=0, redraw= True ),
transition=dict( duration=0)
)
],
#label='Date : {}'.format(date_range[k])
) for k in range(0,len(frames))],
transition= dict(duration=0),
x=0,
y=0,
currentvalue=dict(font=dict(size=12), visible=True, xanchor= 'center'),
len=1.0)
]
trace1 = go.Surface(x=xx1, y=xx2, z=fx, showscale=False, opacity=0.6)
trace2 = go.Scatter3d(x=None, y=None, z=None)
fig = go.Figure(data=[trace1, trace2], frames=frames)
fig.update_layout(updatemenus=[dict(type="buttons", buttons=[dict(label="Play", method="animate", args=[None, dict(fromcurrent=True)]), \
dict(label="Pause", method="animate", args=[[None], \
dict(fromcurrent=True, mode='immediate', transition= {'duration': 0}, frame=dict(redraw=True, duration=0))])])],
margin=dict(r=20, l=10, b=10, t=10), sliders=sliders)
fig.show()

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@ -1,101 +0,0 @@
import copy
import time
import sympy
import numpy as np
from scipy.misc import derivative
from sympy import symbols, sympify, lambdify, diff
import ipywidgets as widgets
from IPython.display import display, clear_output
from tqdm import tqdm
import matplotlib.pyplot as plt
import plotly.graph_objects as go
import plotly.io as pio
import warnings
warnings.filterwarnings("ignore")
class gradient_descent_1d(object):
def __init__(self, environ:str="jupyterlab"):
pio.renderers.default = environ # 'notebook' or 'colab' or 'jupyterlab'
self.wg_expr = widgets.Text(value="x**3 - x**(1/2)",
description="Expression:",
style={'description_width': 'initial'})
self.wg_x0 = widgets.FloatText(value="2",
description="Startpoint:",
style={'description_width': 'initial'})
self.wg_lr = widgets.FloatText(value="1e-1",
description="step size:",
style={'description_width': 'initial'})
self.wg_epsilon = widgets.FloatText(value="1e-5",
description="criterion:",
style={'description_width': 'initial'})
self.wg_max_iter = widgets.IntText(value="1000",
description="max iteration",
style={'description_width': 'initial'})
self.button_compute = widgets.Button(description="Compute")
self.button_plot = widgets.Button(description="Plot")
self.compute_output = widgets.Output()
self.plot_output = widgets.Output()
self.params_lvbox = widgets.VBox([self.wg_expr, self.wg_x0, self.wg_lr])
self.params_rvbox = widgets.VBox([self.wg_epsilon, self.wg_max_iter])
self.params_box = widgets.HBox([self.params_lvbox, self.params_rvbox], description="Parameters")
self.button_box = widgets.HBox([self.button_compute, self.button_plot], description="operations")
self.config = widgets.VBox([self.params_box, self.button_box])
self.initialization()
def initialization(self):
display(self.config)
self.button_compute.on_click(self.compute)
display(self.compute_output)
self.button_plot.on_click(self.plot)
display(self.plot_output)
def compute(self, *args):
with self.compute_output:
xn = self.wg_x0.value
x = symbols("x")
expr = sympify(self.wg_expr.value)
f = lambdify(x, expr)
df = lambdify(x, diff(expr, x))
self.xn_list, self.df_list = [], []
for n in tqdm(range(0, self.wg_max_iter.value)):
gradient = df(xn)
self.xn_list.append(xn)
self.df_list.append(gradient)
if abs (gradient < self.wg_epsilon.value):
clear_output(wait=True)
print("Found solution of {} after".format(expr), n, "iterations")
print("x* = {}".format(xn))
return None
xn = xn - self.wg_lr.value * gradient
clear_output(wait=True)
display("Exceeded maximum iterations. No solution found.")
return None
def plot(self, *args):
with self.plot_output:
clear_output(wait=True)
x0 = float(self.wg_x0.value)
x = symbols("x")
expr = sympify(self.wg_expr.value)
f = lambdify(x, sympify(expr), "numpy")
xx1 = np.arange(np.array(self.xn_list).min()*0.5, np.array(self.xn_list).max()*1.5, 0.05)
fx = f(xx1)
f_xn = f(np.array(self.xn_list))
fig = go.Figure()
fig.add_scatter(x=xx1, y=fx)
frames = []
frames.append({'data':copy.deepcopy(fig['data']),'name':f'frame{0}'})
fig.add_traces(go.Scatter(x=None, y=None, mode="lines + markers", line={"color":"#de1032", "width":5}))
frames = [go.Frame(data= [go.Scatter(x=np.array(self.xn_list)[:k], y=f_xn)],traces= [1],name=f'frame{k+2}')for k in range(len(f_xn))]
fig.update(frames=frames)
fig.update_layout(updatemenus=[dict(type="buttons",buttons=[dict(label="Play",method="animate",args=[None])])])
fig.show()

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@ -1,489 +0,0 @@
import copy
import time
import sympy
import numpy as np
from scipy.misc import derivative
from sympy import symbols, sympify, lambdify, diff
import ipywidgets as widgets
from IPython.display import display, clear_output
from tqdm import tqdm
import matplotlib.pyplot as plt
import plotly.graph_objects as go
import plotly.io as pio
import warnings
warnings.filterwarnings("ignore")
class gradient_descent_1d(object):
def __init__(self, environ:str="jupyterlab"):
pio.renderers.default = environ # 'notebook' or 'colab' or 'jupyterlab'
self.wg_expr = widgets.Text(value="x**3 - x**(1/2)",
description="Expression:",
style={'description_width': 'initial'})
self.wg_x0 = widgets.FloatText(value="2",
description="Startpoint:",
style={'description_width': 'initial'})
self.wg_lr = widgets.FloatText(value="1e-1",
description="step size:",
style={'description_width': 'initial'})
self.wg_epsilon = widgets.FloatText(value="1e-5",
description="criterion:",
style={'description_width': 'initial'})
self.wg_max_iter = widgets.IntText(value="1000",
description="max iteration",
style={'description_width': 'initial'})
self.button_compute = widgets.Button(description="Compute")
self.button_plot = widgets.Button(description="Plot")
self.compute_output = widgets.Output()
self.plot_output = widgets.Output()
self.params_lvbox = widgets.VBox([self.wg_expr, self.wg_x0, self.wg_lr])
self.params_rvbox = widgets.VBox([self.wg_epsilon, self.wg_max_iter])
self.params_box = widgets.HBox([self.params_lvbox, self.params_rvbox], description="Parameters")
self.button_box = widgets.HBox([self.button_compute, self.button_plot], description="operations")
self.config = widgets.VBox([self.params_box, self.button_box])
self.initialization()
def initialization(self):
display(self.config)
self.button_compute.on_click(self.compute)
display(self.compute_output)
self.button_plot.on_click(self.plot)
display(self.plot_output)
def compute(self, *args):
with self.compute_output:
xn = self.wg_x0.value
x = symbols("x")
expr = sympify(self.wg_expr.value)
f = lambdify(x, expr)
df = lambdify(x, diff(expr, x))
self.xn_list, self.df_list = [], []
for n in tqdm(range(0, self.wg_max_iter.value)):
gradient = df(xn)
self.xn_list.append(xn)
self.df_list.append(gradient)
if abs (gradient < self.wg_epsilon.value):
clear_output(wait=True)
print("Found solution of {} after".format(expr), n, "iterations")
print("x* = {}".format(xn))
return None
xn = xn - self.wg_lr.value * gradient
clear_output(wait=True)
display("Exceeded maximum iterations. No solution found.")
return None
def plot(self, *args):
with self.plot_output:
clear_output(wait=True)
x0 = float(self.wg_x0.value)
x = symbols("x")
expr = sympify(self.wg_expr.value)
f = lambdify(x, sympify(expr), "numpy")
xx1 = np.arange(np.array(self.xn_list).min()*0.5, np.array(self.xn_list).max()*1.5, 0.05)
fx = f(xx1)
f_xn = f(np.array(self.xn_list))
fig = go.Figure()
fig.add_scatter(x=xx1, y=fx)
frames = []
frames.append({'data':copy.deepcopy(fig['data']),'name':f'frame{0}'})
fig.add_traces(go.Scatter(x=None, y=None, mode="lines + markers", line={"color":"#de1032", "width":5}))
frames = [go.Frame(data= [go.Scatter(x=np.array(self.xn_list)[:k], y=f_xn)],traces= [1],name=f'frame{k+2}')for k in range(len(f_xn))]
fig.update(frames=frames)
fig.update_layout(updatemenus=[dict(type="buttons",buttons=[dict(label="Play",method="animate",args=[None])])])
fig.show()
class gradient_descent_2d(object):
def __init__(self, environ:str="jupyterlab"):
pio.renderers.default = environ # 'notebook' or 'colab' or 'jupyterlab'
self.wg_expr = widgets.Dropdown(options=[("(sin(x1) - 2) + (sin(x2) - 2) ** 2", "(sin(x1) - 2) + (sin(x2) - 2) ** 2"),
("(sin(x1) - 2) ** (1/2) + (sin(x2) - 2) ** 2", "(sin(x1) - 2) ** (1/2) + (sin(x2) - 2) ** 2"),
("(sin(x1) - 2) ** 2 + (sin(x2) - 2) ** 2", "(sin(x1) - 2) ** 2 + (sin(x2) - 2) ** 2")],
value="(sin(x1) - 2) ** 2 + (sin(x2) - 2) ** 2", descrption="Expression")
self.wg_x0 = widgets.Text(value="5,5",
description="Startpoint:")
self.wg_lr = widgets.FloatText(value="1e-1",
description="step size:")
self.wg_epsilon = widgets.FloatText(value="1e-5",
description="criterion:")
self.wg_max_iter = widgets.IntText(value="1000",
description="max iteration")
self.button_compute = widgets.Button(description="Compute")
self.button_plot = widgets.Button(description="Plot")
self.compute_output = widgets.Output()
self.plot_output = widgets.Output()
self.params_lvbox = widgets.VBox([self.wg_x0, self.wg_lr])
self.params_rvbox = widgets.VBox([self.wg_epsilon, self.wg_max_iter])
self.exp_box = widgets.HBox([self.wg_expr])
self.params_box = widgets.HBox([self.params_lvbox, self.params_rvbox], description="Parameters")
self.button_box = widgets.HBox([self.button_compute, self.button_plot], description="operations")
self.config = widgets.VBox([self.exp_box, self.params_box, self.button_box])
self.initialization()
def initialization(self):
display(self.config)
self.button_compute.on_click(self.compute)
display(self.compute_output)
self.button_plot.on_click(self.plot)
display(self.plot_output)
def compute(self, *args):
with self.compute_output:
x0 = np.array(self.wg_x0.value.split(","), dtype=float)
xn = x0
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
self.xn_list, self.df_list = [], []
for n in tqdm(range(0, self.wg_max_iter.value)):
gradient = np.array([diff(expr, x1).subs(x1, xn[0]).subs(x2, xn[1]),
diff(expr, x2).subs(x1, xn[0]).subs(x2, xn[1])], dtype=float)
self.xn_list.append(xn)
self.df_list.append(gradient)
if np.linalg.norm(gradient, ord=2) < self.wg_epsilon.value:
clear_output(wait=True)
print("Found solution of {} after".format(expr), n, "iterations")
print("x* = [{}, {}]".format(xn[0], xn[1]))
return None
xn = xn - self.wg_lr.value * gradient
clear_output(wait=True)
display("Exceeded maximum iterations. No solution found.")
return None
def plot(self, *args):
with self.plot_output:
clear_output(wait=True)
x0 = np.array(self.wg_x0.value.split(","), dtype=float)
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
xx1 = np.arange(np.array(self.xn_list)[:, 0].min() * 0.5, np.array(self.xn_list)[:, 0].max() * 1.5, 0.1)
xx2 = np.arange(np.array(self.xn_list)[:, 1].min() * 0.5, np.array(self.xn_list)[:, 1].max() * 1.5, 0.1)
xx1_tangent = np.arange(np.array(self.xn_list)[:, 0].min(), np.array(self.xn_list)[:, 0].max(), 0.1)
xx2_tangent = np.arange(np.array(self.xn_list)[:, 1].min(), np.array(self.xn_list)[:, 1].max(), 0.1)
xx1_o, xx2_o = xx1, xx2
xx1, xx2 = np.meshgrid(xx1, xx2)
xx1_tangent, xx2_tangent = np.meshgrid(xx1_tangent, xx2_tangent)
f = lambdify((x1, x2), expr, "numpy")
fx = f(xx1, xx2)
f_xn = f(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1])
partial_x1 = lambdify((x1, x2), diff(expr, x1), "numpy")
partial_x2 = lambdify((x1, x2), diff(expr, x2), "numpy")
plane = partial_x1(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1]) * (x1 - np.array(self.xn_list)[:, 0]) + partial_x2(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1]) * (x2 - np.array(self.xn_list)[:, 1]) + f_xn
z = [lambdify((x1, x2), plane[i], "numpy")(xx1_tangent, xx2_tangent) for i in range(0, len(plane))]
frames, steps = [], []
for k in range(len(f_xn)):
tmp_trace1 = go.Scatter3d(x=np.array(self.xn_list)[:k,0], y=np.array(self.xn_list)[:k,1], z=f_xn)
tmp_trace2 = go.Surface(x=xx1_tangent, y=xx2_tangent, z=z[k], showscale=True, opacity=0.5)
frame = go.Frame(dict(data=[tmp_trace1, tmp_trace2], name=f'frame{k+1}'), traces=[1, 2])
frames.append(frame)
step = dict(
method="update",
args=[{"visible": [True]},
{"title": "Slider switched to step: " + str(k+1)}], # layout attribute
)
steps.append(step)
sliders = [dict(steps= [dict(method= 'animate',
args= [[f'frame{k+1}'],
dict(mode= 'immediate',
frame= dict( duration=0, redraw= True ),
transition=dict( duration=0)
)
],
#label='Date : {}'.format(date_range[k])
) for k in range(0,len(frames))],
transition= dict(duration=0),
x=0,
y=0,
currentvalue=dict(font=dict(size=12), visible=True, xanchor= 'center'),
len=1.0)
]
trace1 = go.Surface(x=xx1, y=xx2, z=fx, showscale=False, opacity=0.6)
trace2 = go.Scatter3d(x=None, y=None, z=None)
trace3 = go.Surface(x=None, y=None, z=None, showscale=False, opacity=0.9, colorscale='Blues')
fig = go.Figure(data=[trace1, trace2, trace3], frames=frames)
fig.update_layout(updatemenus=[dict(type="buttons", buttons=[dict(label="Play", method="animate", args=[None, dict(fromcurrent=True)]), \
dict(label="Pause", method="animate", args=[[None], \
dict(fromcurrent=True, mode='immediate', transition= {'duration': 0}, frame=dict(redraw=True, duration=0))])])],
margin=dict(r=20, l=10, b=10, t=10), sliders=sliders)
fig.show()
class gradient_descent_2d_custom(object):
def __init__(self, environ:str="jupyterlab"):
pio.renderers.default = environ # 'notebook' or 'colab' or 'jupyterlab'
self.wg_expr = widgets.Text(value="(sin(x1) - 2) ** 2 + (sin(x2) - 2) ** 2", description="Expression:")
self.wg_x0 = widgets.Text(value="5,5", description="Startpoint:")
self.wg_lr = widgets.FloatText(value="1e-1", description="step size:")
self.wg_epsilon = widgets.FloatText(value="1e-5", description="criterion:")
self.wg_max_iter = widgets.IntText(value="1000", description="max iteration")
self.button_compute = widgets.Button(description="Compute")
self.button_plot = widgets.Button(description="Plot")
self.compute_output = widgets.Output()
self.plot_output = widgets.Output()
self.params_lvbox = widgets.VBox([self.wg_expr, self.wg_x0, self.wg_lr])
self.params_rvbox = widgets.VBox([self.wg_epsilon, self.wg_max_iter])
self.params_box = widgets.HBox([self.params_lvbox, self.params_rvbox], description="Parameters")
self.button_box = widgets.HBox([self.button_compute, self.button_plot], description="operations")
self.config = widgets.VBox([self.params_box, self.button_box])
self.initialization()
def initialization(self):
display(self.config)
self.button_compute.on_click(self.compute)
display(self.compute_output)
self.button_plot.on_click(self.plot)
display(self.plot_output)
def compute(self, *args):
with self.compute_output:
x0 = np.array(self.wg_x0.value.split(","), dtype=float)
xn = x0
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
self.xn_list, self.df_list = [], []
for n in tqdm(range(0, self.wg_max_iter.value)):
gradient = np.array([diff(expr, x1).subs(x1, xn[0]).subs(x2, xn[1]),
diff(expr, x2).subs(x1, xn[0]).subs(x2, xn[1])], dtype=float)
self.xn_list.append(xn)
self.df_list.append(gradient)
if np.linalg.norm(gradient, ord=2) < self.wg_epsilon.value:
clear_output(wait=True)
print("Found solution of {} after".format(expr), n, "iterations")
print("x* = [{}, {}]".format(xn[0], xn[1]))
return None
xn = xn - self.wg_lr.value * gradient
clear_output(wait=True)
display("Exceeded maximum iterations. No solution found.")
return None
def plot(self, *args):
with self.plot_output:
clear_output(wait=True)
x0 = np.array(self.wg_x0.value.split(","), dtype=float)
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
xx1 = np.arange(np.array(self.xn_list)[:, 0].min()*0.5, np.array(self.xn_list)[:, 0].max()*1.5, 0.05)
xx2 = np.arange(np.array(self.xn_list)[:, 1].min()*0.5, np.array(self.xn_list)[:, 1].max()*1.5, 0.05)
xx1, xx2 = np.meshgrid(xx1, xx2)
f = lambdify((x1, x2), expr, "numpy")
fx = f(xx1, xx2)
f_xn = f(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1])
frames, steps = [], []
for k in range(len(f_xn)):
#frame = go.Frame(data=[go.Surface(x=xx1, y=xx2, z=fx, showscale=True, opacity=0.8)])
#fig.add_trace(go.Scatter3d(x=np.array(self.xn_list)[:k, 0], y=np.array(self.xn_list)[:k, 1], z=f_xn))
frame = go.Frame(dict(data=[go.Scatter3d(x=np.array(self.xn_list)[:k,0], y=np.array(self.xn_list)[:k,1], z=f_xn)], name=f'frame{k+1}'), traces=[1])
frames.append(frame)
step = dict(
method="update",
args=[{"visible": [True]},
{"title": "Slider switched to step: " + str(k+1)}], # layout attribute
)
steps.append(step)
sliders = [dict(steps= [dict(method= 'animate',
args= [[f'frame{k+1}'],
dict(mode= 'immediate',
frame= dict( duration=0, redraw= True ),
transition=dict( duration=0)
)
],
#label='Date : {}'.format(date_range[k])
) for k in range(0,len(frames))],
transition= dict(duration=0),
x=0,
y=0,
currentvalue=dict(font=dict(size=12), visible=True, xanchor= 'center'),
len=1.0)
]
trace1 = go.Surface(x=xx1, y=xx2, z=fx, showscale=True, opacity=0.8)
trace2 = go.Scatter3d(x=None, y=None, z=None)
fig = go.Figure(data=[trace1, trace2], frames=frames)
#fig.add_surface(x=xx1, y=xx2, z=fx, showscale=True, opacity=0.9)
#fig.update_traces(contours_z=dict(show=True, usecolormap=True, highlightcolor="limegreen", project_z=True))
#fig.update(frames=frames)
fig.update_layout(updatemenus=[dict(type="buttons", buttons=[dict(label="Play", method="animate", args=[None, dict(fromcurrent=True)]), \
dict(label="Pause", method="animate", args=[[None], dict(fromcurrent=True, mode='immediate', transition= {'duration': 0}, frame=dict(redraw=True, duration=0))])])],
margin=dict(l=0, r=0, b=0, t=0), sliders=sliders)
fig.show()
class gradient_descent_2d_race(object):
def __init__(self, environ:str="jupyterlab"):
pio.renderers.default = environ # 'notebook' or 'colab' or 'jupyterlab'
self.wg_expr = widgets.Text(value="(sin(x1) - 2) ** 2 + (sin(x2) - 2) ** 2", description="Expression:")
self.wg_person_one = widgets.Text(value="(5, 5)", description="candidate 1:")
self.wg_person_two = widgets.Text(value="(5, 5)", description="candidate 2:")
self.button_compute = widgets.Button(description="Compute")
self.button_plot = widgets.Button(description="Plot")
self.compute_output = widgets.Output()
self.plot_output = widgets.Output()
self.button_box = widgets.HBox([self.button_compute, self.button_plot], description="operations")
self.config = widgets.VBox([self.wg_expr, self.wg_person_one, self.wg_person_two, self.button_box])
self.xn_list_p1, self.df_list_p1 = [], []
self.xn_list_p2, self.df_list_p2 = [], []
self.initialization()
def initialization(self):
display(self.config)
self.button_compute.on_click(self.compute)
display(self.compute_output)
self.button_plot.on_click(self.plot)
display(self.plot_output)
def compute(self, *args):
with self.compute_output:
# person_one
x0 = np.array(self.wg_person_one.value.split("(")[1].split(")")[0].split(","), dtype=float)
xn = x0
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
gradient = np.array([diff(expr, x1).subs(x1, xn[0]).subs(x2, xn[1]),
diff(expr, x2).subs(x1, xn[0]).subs(x2, xn[1])], dtype=float)
self.xn_list_p1.append(xn)
self.df_list_p1.append(gradient)
print("player one: x = [{}, {}]".format(xn[0], xn[1]))
print("player one: gradient= {}".format(gradient))
# person_two
x0 = np.array(self.wg_person_two.value.split("(")[1].split(")")[0].split(","), dtype=float)
xn = x0
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
gradient = np.array([diff(expr, x1).subs(x1, xn[0]).subs(x2, xn[1]),
diff(expr, x2).subs(x1, xn[0]).subs(x2, xn[1])], dtype=float)
self.xn_list_p2.append(xn)
self.df_list_p2.append(gradient)
print("player two: x = [{}, {}]".format(xn[0], xn[1]))
print("player two: gradient= {}".format(gradient))
clear_output(wait=True)
return None
def plot(self, *args):
with self.plot_output:
clear_output(wait=True)
#x0 = np.array(self.wg_x0.value.split(","), dtype=float)
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
xx1 = np.arange(np.array(self.xn_list_p1)[:, 0].min()*0.5, np.array(self.xn_list_p1)[:, 0].max()*1.5, 0.1)
xx2 = np.arange(np.array(self.xn_list_p1)[:, 1].min()*0.5, np.array(self.xn_list_p1)[:, 1].max()*1.5, 0.1)
xx1, xx2 = np.meshgrid(xx1, xx2)
f = lambdify((x1, x2), expr, "numpy")
fx = f(xx1, xx2)
f_xn_p1 = f(np.array(self.xn_list_p1)[:, 0], np.array(self.xn_list_p1)[:, 1])
f_xn_p2 = f(np.array(self.xn_list_p2)[:, 0], np.array(self.xn_list_p2)[:, 1])
frames, steps = [], []
for k in range(len(f_xn_p1)):
tmp_trace1 = go.Scatter3d(x=np.array(self.xn_list_p1)[:k,0], y=np.array(self.xn_list_p1)[:k,1], z=f_xn_p1)
tmp_trace2 = go.Scatter3d(x=np.array(self.xn_list_p2)[:k,0], y=np.array(self.xn_list_p2)[:k,1], z=f_xn_p2)
frame = go.Frame(dict(data=[tmp_trace1, tmp_trace2], name=f'frame{k+1}'), traces=[1, 2])
frames.append(frame)
step = dict(
method="update",
args=[{"visible": [True]},
{"title": "Slider switched to step: " + str(k+1)}], # layout attribute
)
steps.append(step)
sliders = [dict(steps= [dict(method= 'animate',
args= [[f'frame{k+1}'],
dict(mode= 'immediate',
frame= dict( duration=0, redraw= True ),
transition=dict( duration=0)
)
],
#label='Date : {}'.format(date_range[k])
) for k in range(0,len(frames))],
transition= dict(duration=0),
x=0,
y=0,
currentvalue=dict(font=dict(size=12), visible=True, xanchor= 'center'),
len=1.0)
]
trace1 = go.Surface(x=xx1, y=xx2, z=fx, showscale=True, opacity=0.4)
trace2 = go.Scatter3d(x=None, y=None, z=None)
trace3 = go.Scatter3d(x=None, y=None, z=None)
fig = go.Figure(data=[trace1, trace2, trace3], frames=frames)
fig.update_layout(updatemenus=[dict(type="buttons", buttons=[dict(label="Play", method="animate", args=[None, dict(fromcurrent=True)]), \
dict(label="Pause", method="animate", args=[[None], dict(fromcurrent=True, mode='immediate', transition= {'duration': 0}, frame=dict(redraw=True, duration=0))])])],
margin=dict(l=20, r=20, b=20, t=20), sliders=sliders)
fig.show()
def plot2(self, *args):
with self.plot_output:
clear_output(wait=True)
#x0 = np.array(self.wg_x0.value.split(","), dtype=float)
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
xx1 = np.arange(np.array(self.xn_list_p1)[:, 0].min()*0.5, np.array(self.xn_list_p1)[:, 0].max()*1.5, 0.1)
xx2 = np.arange(np.array(self.xn_list_p1)[:, 1].min()*0.5, np.array(self.xn_list_p1)[:, 1].max()*1.5, 0.1)
xx1, xx2 = np.meshgrid(xx1, xx2)
f = lambdify((x1, x2), expr, "numpy")
fx = f(xx1, xx2)
f_xn_p1 = f(np.array(self.xn_list_p1)[:, 0], np.array(self.xn_list_p1)[:, 1])
f_xn_p2 = f(np.array(self.xn_list_p2)[:, 0], np.array(self.xn_list_p2)[:, 1])
frames, steps = [], []
for k in range(len(f_xn_p1)):
tmp_trace1 = go.Scatter3d(x=np.array(self.xn_list_p1)[:k,0], y=np.array(self.xn_list_p1)[:k,1], z=f_xn_p1)
tmp_trace2 = go.Scatter3d(x=np.array(self.xn_list_p2)[:k,0], y=np.array(self.xn_list_p2)[:k,1], z=f_xn_p2)
frame = go.Frame(dict(data=[tmp_trace1, tmp_trace2], name=f'frame{k+1}'), traces=[1, 2])
frames.append(frame)
step = dict(
method="update",
args=[{"visible": [True]},
{"title": "Slider switched to step: " + str(k+1)}], # layout attribute
)
steps.append(step)
sliders = [dict(steps= [dict(method= 'animate',
args= [[f'frame{k+1}'],
dict(mode= 'immediate',
frame= dict( duration=0, redraw= True ),
transition=dict( duration=0)
)
],
#label='Date : {}'.format(date_range[k])
) for k in range(0,len(frames))],
transition= dict(duration=0),
x=0,
y=0,
currentvalue=dict(font=dict(size=12), visible=True, xanchor= 'center'),
len=1.0)
]
trace1 = go.Surface(x=xx1, y=xx2, z=fx, showscale=True, opacity=0.4)
trace2 = go.Scatter3d(x=None, y=None, z=None)
trace3 = go.Scatter3d(x=None, y=None, z=None)
fig = go.Figure(data=[trace1, trace2, trace3], frames=frames)
fig.update_layout(updatemenus=[dict(type="buttons", buttons=[dict(label="Play", method="animate", args=[None, dict(fromcurrent=True)]), \
dict(label="Pause", method="animate", args=[[None], dict(fromcurrent=True, mode='immediate', transition= {'duration': 0}, frame=dict(redraw=True, duration=0))])])],
margin=dict(l=20, r=20, b=20, t=20), sliders=sliders)
fig.show()

View File

@ -1,129 +0,0 @@
import copy
import time
import sympy
import numpy as np
from scipy.misc import derivative
from sympy import symbols, sympify, lambdify, diff
import ipywidgets as widgets
from IPython.display import Image, display, clear_output
from tqdm import tqdm
import matplotlib.pyplot as plt
import plotly.graph_objects as go
import plotly.io as pio
import warnings
warnings.filterwarnings("ignore")
class gd_2d_test(object):
def __init__(self, environ:str="jupyterlab", type="default"):
if type == "default":
self.initialization_default(environ=environ)
self.compute_default()
self.user_step = 1
elif type == "custom":
self.initlization_custom()
self.compute_custom()
else:
return None
def initialization_default(self, environ):
pio.renderers.default = environ # 'notebook' or 'colab' or 'jupyterlab'
self.wg_expr = widgets.Dropdown(options=[("(1 - 8 * x1 + 7 * x1**2 - (7/3) * x1**3 + (1/4) * x1**4) * x2**2 * E**(-x2)", "(1 - 8 * x1 + 7 * x1**2 - (7/3) * x1**3 + (1/4) * x1**4) * x2**2 * E**(-x2)"), ("(sin(x1) - 2) ** 2 + (sin(x2) - 2) ** 2", "(sin(x1) - 2) ** 2 + (sin(x2) - 2) ** 2")], value="(1 - 8 * x1 + 7 * x1**2 - (7/3) * x1**3 + (1/4) * x1**4) * x2**2 * E**(-x2)", descrption="Expression")
self.wg_x0 = widgets.Text(value="0,2", description="Startpoint:")
self.wg_lr = widgets.FloatText(value="1e-1", description="step size:")
self.wg_epsilon = widgets.FloatText(value="1e-5", description="criterion:")
self.wg_max_iter = widgets.IntText(value="1000", description="max iteration")
self.button_compute = widgets.Button(description="Compute")
self.button_plot_default = widgets.Button(description="Plot")
self.compute_output = widgets.Output()
self.plot_default_output = widgets.Output()
self.params_lvbox = widgets.VBox([self.wg_x0, self.wg_lr])
self.params_rvbox = widgets.VBox([self.wg_epsilon, self.wg_max_iter])
self.exp_box = widgets.HBox([self.wg_expr])
self.params_box = widgets.HBox([self.params_lvbox, self.params_rvbox], description="Parameters")
self.button_box = widgets.HBox([self.button_compute, self.button_plot_default], description="operations")
self.config = widgets.VBox([self.exp_box, self.params_box, self.button_box])
display(self.config)
self.button_compute.on_click(self.compute_default)
display(self.compute_output)
self.button_plot_default.on_click(self.plot_default)
img1 = self.plot_default_output
display(img1)
def compute_default(self, *args):
with self.compute_output:
x0 = np.array(self.wg_x0.value.split(","), dtype=float)
xn = x0
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
self.xn_list, self.df_list = [], []
for n in tqdm(range(0, self.wg_max_iter.value)):
gradient = np.array([diff(expr, x1).subs(x1, xn[0]).subs(x2, xn[1]),
diff(expr, x2).subs(x1, xn[0]).subs(x2, xn[1])], dtype=float)
self.xn_list.append(xn)
self.df_list.append(gradient)
if np.linalg.norm(gradient, ord=2) < self.wg_epsilon.value:
clear_output(wait=True)
print("Found solution of {} after".format(expr), n, "iterations")
print("x* = [{}, {}]".format(xn[0], xn[1]))
return None
xn = xn - self.wg_lr.value * gradient
clear_output(wait=True)
display("Exceeded maximum iterations. No solution found.")
return None
def plot_default(self, *args):
with self.plot_default_output:
clear_output(wait=True)
x0 = np.array(self.wg_x0.value.split(","), dtype=float)
x1 = symbols("x1")
x2 = symbols("x2")
expr = sympify(self.wg_expr.value)
xx1 = np.arange(0, 5, 0.1)
xx2 = np.arange(0, 6, 0.1)
#xx1 = np.arange(np.array(self.xn_list)[:, 0].min() * 0.5, np.array(self.xn_list)[:, 0].max() * 1.5, 0.1)
#xx2 = np.arange(np.array(self.xn_list)[:, 1].min() * 0.5, np.array(self.xn_list)[:, 1].max() * 1.5, 0.1)
xx1_tangent = np.arange(np.array(self.xn_list)[:, 0].min(), np.array(self.xn_list)[:, 0].max(), 0.1)
xx2_tangent = np.arange(np.array(self.xn_list)[:, 1].min(), np.array(self.xn_list)[:, 1].max(), 0.1)
xx1_o, xx2_o = xx1, xx2
xx1, xx2 = np.meshgrid(xx1, xx2)
xx1_tangent, xx2_tangent = np.meshgrid(xx1_o, xx2_o)
f = lambdify((x1, x2), expr, "numpy")
fx = f(xx1, xx2)
f_xn = f(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1])
partial_x1 = lambdify((x1, x2), diff(expr, x1), "numpy")
partial_x2 = lambdify((x1, x2), diff(expr, x2), "numpy")
plane = partial_x1(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1]) * (x1 - np.array(self.xn_list)[:, 0]) + partial_x2(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1]) * (x2 - np.array(self.xn_list)[:, 1]) + f_xn
z = [lambdify((x1, x2), plane[i], "numpy")(xx1_tangent, xx2_tangent) for i in range(0, len(plane))]
from plotly.subplots import make_subplots
import plotly.express as px
df = px.data.tips()
fig = px.density_contour(df, x="total_bill", y="tip")
fig = make_subplots(rows=1, cols=2, specs=[[{'type': 'surface'}, {'type': 'xy'}]])
fig.add_trace(go.Surface(contours = {"x": {"show": True}, "y":{"show": True}, "z":{"show": True}},x=xx1, y=xx2, z=fx), row=1, col=1)
fig.add_trace(go.Scatter3d(x=None, y=None, z=None), row=1, col=1)
fig.add_trace(go.Surface(x=None, y=None, z=None, showscale=False, colorscale='Blues'), row=1, col=1)
fig.add_trace(go.Contour(x=xx1_o, y=xx2_o, z=fx), row=1, col=2)
fig.add_trace(go.Scatter(x=None, y=None), row=1, col=2)
frames = [go.Frame(data=[go.Surface(visible=True, showscale=False, opacity=0.8),
go.Scatter3d(x=np.array(self.xn_list)[:k,0], y=np.array(self.xn_list)[:k,1], z=f_xn),
go.Surface(x=xx1_tangent, y=xx2_tangent, z=z[k]),
go.Contour(visible=True),
go.Scatter(x=np.array(self.xn_list)[:k, 0], y=np.array(self.xn_list)[:k, 1])],
traces=[0, 1, 2, 3, 4]) for k in range(len(f_xn))]
fig.frames = frames
fig.update_layout(autosize=False, height=800, updatemenus=[dict(type="buttons", buttons=[dict(label="Play", method="animate", args=[None, dict(fromcurrent=True, transition= {'duration': 0}, frame=dict(redraw=True, duration=500))]), \
dict(label="Pause", method="animate", args=[[None], \
dict(fromcurrent=True, mode='immediate', transition={'duration': 0}, frame=dict(redraw=True, duration=0))])])])
fig.show()

View File

@ -30,7 +30,7 @@ def array_mesh(data, n):
class gd_1d(object):
def __init__(self, environ:str="jupyterlab"):
pio.renderers.default = environ # 'notebook' or 'colab' or 'jupyterlab'
self.wg_expr = widgets.Text(value="-2 * x * sin(-(pi/4) * x)+10",
self.wg_expr = widgets.Text(value="sin(x) + sin((10.0 / 3.0) * x)",
description="Expression:",
style={'description_width': 'initial'})
self.wg_x0 = widgets.FloatText(value="2",
@ -45,6 +45,9 @@ class gd_1d(object):
self.wg_max_iter = widgets.IntText(value="1000",
description="max iteration",
style={'description_width': 'initial'})
self.wg_x_range = widgets.Text(value="-5,5",
description="X-axis range",
style={"description_width": "initial"})
self.button_compute = widgets.Button(description="Compute")
self.button_plot = widgets.Button(description="Plot")
@ -52,7 +55,7 @@ class gd_1d(object):
self.compute_output = widgets.Output()
self.plot_output = widgets.Output()
self.params_lvbox = widgets.VBox([self.wg_expr, self.wg_x0, self.wg_lr])
self.params_rvbox = widgets.VBox([self.wg_epsilon, self.wg_max_iter])
self.params_rvbox = widgets.VBox([self.wg_epsilon, self.wg_max_iter, self.wg_x_range])
self.params_box = widgets.HBox([self.params_lvbox, self.params_rvbox], description="Parameters")
self.button_box = widgets.HBox([self.button_compute, self.button_plot], description="operations")
self.config = widgets.VBox([self.params_box, self.button_box])
@ -93,11 +96,11 @@ class gd_1d(object):
with self.plot_output:
clear_output(wait=True)
x0 = float(self.wg_x0.value)
x_range = np.array(self.wg_x_range.value.split(","), dtype=float)
x = symbols("x")
expr = sympify(self.wg_expr.value)
f = lambdify(x, sympify(expr), "numpy")
#xx1 = np.arange(np.array(self.xn_list).min()*0.5, np.array(self.xn_list).max()*1.5, 0.05)
xx1 = np.arange(0, 10, 0.05)
xx1 = np.arange(x_range[0], x_range[1], 0.05)
fx = f(xx1)
f_xn = f(np.array(self.xn_list))
@ -133,8 +136,8 @@ class gd_2d(object):
self.wg_epsilon = widgets.FloatText(value="1e-5", description="criterion:")
self.wg_max_iter = widgets.IntText(value="1000", description="max iteration")
self.button_compute = widgets.Button(description="Compute")
self.button_plot_default = widgets.Button(description="Plot")
self.button_plot_contour = widgets.Button(description="Plot contour")
self.button_plot_default = widgets.Button(description="3D Plot")
self.button_plot_contour = widgets.Button(description="Contour")
self.compute_output = widgets.Output()
self.plot_default_output = widgets.Output()
@ -197,13 +200,16 @@ class gd_2d(object):
xx1_o, xx2_o = xx1, xx2
xx1, xx2 = np.meshgrid(xx1, xx2)
xx1_tangent, xx2_tangent = np.meshgrid(xx1_o, xx2_o)
#xx1_tangent, xx2_tangent = array_mesh(np.arange(0, 5, 0.25), 10), array_mesh(np.arange(0, 5, 0.25), 10)
self.xx1_tangent, self.xx2_tangent = xx1_tangent, xx2_tangent
f = lambdify((x1, x2), expr, "numpy")
fx = f(xx1, xx2)
f_xn = f(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1])
partial_x1 = lambdify((x1, x2), diff(expr, x1), "numpy")
partial_x2 = lambdify((x1, x2), diff(expr, x2), "numpy")
self.partial_x1, self.partial_x2 = partial_x1, partial_x2
plane = partial_x1(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1]) * (x1 - np.array(self.xn_list)[:, 0]) + partial_x2(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1]) * (x2 - np.array(self.xn_list)[:, 1]) + f_xn
z = [lambdify((x1, x2), plane[i], "numpy")(xx1_tangent, xx2_tangent) for i in range(0, len(plane))]
self.z = z
## projection
@ -215,13 +221,13 @@ class gd_2d(object):
fig = make_subplots(rows=1, cols=2, specs=[[{'type': 'surface'}, {'type': 'surface'}]])
fig.add_trace(go.Surface(contours = {"x": {"show": True}, "y":{"show": True}, "z":{"show": True}}, x=xx1, y=xx2, z=fx), row=1, col=1)
fig.add_trace(go.Scatter3d(x=None, y=None, z=None), row=1, col=1)
fig.add_trace(go.Surface(x=xx1_tangent, y=xx2_tangent, z=z[0], showscale=False, colorscale='Blues'), row=1, col=1)
fig.add_trace(go.Surface(x=None, y=None, z=None, showlegend=False, showscale=False, colorscale='Blues'), row=1, col=1)
fig.add_trace(go.Surface(z=list(z_offset), x=xx1, y=xx2, showlegend=False, showscale=False, surfacecolor=colorsurfz), row=1, col=2)
fig.add_trace(go.Scatter3d(x=None, y=None, z=None), row=1, col=2)
fig.add_trace(go.Scatter3d(x=None, y=None, z=None), row=1, col=2)
frames = [go.Frame(data=[go.Surface(visible=True, showscale=False, opacity=0.8),
go.Scatter3d(x=np.array(self.xn_list)[:k,0], y=np.array(self.xn_list)[:k,1], z=f_xn),
go.Surface(visible=True, x=xx1_tangent, y=xx2_tangent, z=z[k]),
go.Surface(visible=False, x=xx1_tangent, y=xx2_tangent, z=z[k]),
go.Surface(visible=True, showscale=False, opacity=0.8),
go.Scatter3d(x=np.array(self.xn_list)[:k, 0], y=np.array(self.xn_list)[:k, 1], z=f_xn),
go.Scatter3d(x=np.array(self.xn_list)[:k, 0].flatten(), y=np.array(self.xn_list)[:k, 1].flatten(), z=z_offset.flatten())],
@ -231,9 +237,13 @@ class gd_2d(object):
button_play = dict(label="Play", method="animate", args=[None, dict(fromcurrent=True, transition=dict(duration=0), frame=dict(redraw=True, duration=1000))])
button_pause = dict(label="Pause", method="animate", args=[[None], dict(fromcurrent=True, mode='immediate', transition={'duration': 0}, frame=dict(redraw=True, duration=0))])
button_quiver = dict(label="Quiver", method="update", args=[{"visible": [False, False, False, False, False, True]}])
button_tangent = dict(label="Tangent Plane", method="update", args=[{"visible": [True, True, True, True, True, True]}])
fig.update_layout(scene_aspectmode='manual', scene_aspectratio=dict(x=0, y=0, z=0),
height=800, updatemenus=[dict(type="buttons", buttons=[button_play, button_pause])])
height=800, updatemenus=[dict(type="buttons", buttons=[button_play, button_pause, button_tangent])])
fig.update_scenes(xaxis_visible=True,
yaxis_visible=True,
zaxis_visible=True)
fig.update_scenes(camera_projection_type = "orthographic")
fig.show()
def plot_contour(self, *args):
@ -260,10 +270,10 @@ class gd_2d(object):
gradfun=[sympy.diff(expr,var) for var in (x1,x2)]
numgradfun=sympy.lambdify([x1,x2], gradfun)
x1_mesh, x2_mesh = np.meshgrid(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1])
x1_mesh, x2_mesh = np.meshgrid(xx1_o, xx2_o)#np.meshgrid(np.array(self.xn_list)[:, 0], np.array(self.xn_list)[:, 1])
graddat=numgradfun(x1_mesh, x2_mesh)
vec_field = ff.create_quiver(x1_mesh, x2_mesh, graddat[0], graddat[1],scale=.05, arrow_scale=.1, angle=math.pi/6)
vec_field = ff.create_quiver(x1_mesh, x2_mesh, graddat[0], graddat[1], scale=.05, arrow_scale=.4, angle=math.pi/3)
vec_field.update_traces(line_color="black")
fig = go.Figure()
fig.add_trace(go.Contour(x=xx1_o, y=xx2_o, z=fx))
@ -272,5 +282,5 @@ class gd_2d(object):
fig.update_layout(
updatemenus=[dict(type = "buttons",direction = "left",
buttons=list([
dict(args=[{"visible":["True", "True"]}], label="Quiver", method="update")]))], height=800)
dict(args=[{"visible":["True", "True"]}], label="Gradient", method="update")]))], height=800)
fig.show()