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https://github.com/Visualize-ML/Book4_Power-of-Matrix.git
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55 lines
1.1 KiB
Python
55 lines
1.1 KiB
Python
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###############
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# Authored by Weisheng Jiang
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# Book 4 | From Basic Arithmetic to Machine Learning
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# Published and copyrighted by Tsinghua University Press
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# Beijing, China, 2022
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###############
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# Bk4_Ch12_01.py
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import numpy as np
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from matplotlib import pyplot as plt
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x1 = np.arange(-2,2,0.05)
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x2 = np.arange(-2,2,0.05)
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xx1_fine, xx2_fine = np.meshgrid(x1,x2)
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a = 0; b = -1; c = 0;
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yy_fine = a*xx1_fine**2 + 2*b*xx1_fine*xx2_fine + c*xx2_fine**2
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# 3D visualization
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fig, ax = plt.subplots()
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ax = plt.axes(projection='3d')
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ax.plot_wireframe(xx1_fine,xx2_fine,yy_fine,
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color = [0.8,0.8,0.8],
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linewidth = 0.25)
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ax.contour3D(xx1_fine,xx2_fine,yy_fine,15,
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cmap = 'RdYlBu_r')
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ax.view_init(elev=30, azim=60)
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ax.xaxis.set_ticks([])
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ax.yaxis.set_ticks([])
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ax.zaxis.set_ticks([])
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plt.tight_layout()
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ax.set_proj_type('ortho')
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plt.show()
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# 2D visualization
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fig, ax = plt.subplots()
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ax.contourf(xx1_fine,xx2_fine,yy_fine,15,
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cmap = 'RdYlBu_r')
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ax.xaxis.set_ticks([])
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ax.yaxis.set_ticks([])
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ax.set_aspect('equal')
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plt.show()
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