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Book4_Power-of-Matrix/Book4_Ch10_Python_Codes/Bk4_Ch10_01.py
Iris Series: From Arithmetic Basics to Machine Learning 4a57ec1bb3 Add files via upload
2023-05-07 09:14:16 -04:00

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Python

###############
# Authored by Weisheng Jiang
# Book 4 | From Basic Arithmetic to Machine Learning
# Published and copyrighted by Tsinghua University Press
# Beijing, China, 2022
###############
# Bk4_Ch10_01.py
import seaborn as sns
import numpy as np
import matplotlib.pyplot as plt
import pandas as pd
from sklearn.datasets import load_iris
# A copy from Seaborn
iris = load_iris()
X = iris.data
y = iris.target
feature_names = ['Sepal length, x1','Sepal width, x2',
'Petal length, x3','Petal width, x4']
# Convert X array to dataframe
X_df = pd.DataFrame(X, columns=feature_names)
#%% Original data, X
X = X_df.to_numpy();
# Gram matrix, G and orthogonal basis V
G = X.T@X
D, V = np.linalg.eig(G)
#%%
def heatmap(Matrices,Titles,Ranges,Equal_tags):
M1 = Matrices[0]
M2 = Matrices[1]
M3 = Matrices[2]
Title_1 = Titles[0]
Title_2 = Titles[1]
Title_3 = Titles[2]
fig, axs = plt.subplots(1, 5, figsize=(12, 3))
plt.sca(axs[0])
ax = sns.heatmap(M1,cmap='RdYlBu_r',
vmin = Ranges[0][0],
vmax = Ranges[0][1],
cbar=False,
xticklabels=False,
yticklabels=False)
if Equal_tags[0] == True:
ax.set_aspect("equal")
plt.title(Title_1)
plt.sca(axs[1])
plt.title('=')
plt.axis('off')
plt.sca(axs[2])
ax = sns.heatmap(M2,cmap='RdYlBu_r',
vmin = Ranges[1][0],
vmax = Ranges[1][1],
cbar=False,
xticklabels=False,
yticklabels=False)
if Equal_tags[1] == True:
ax.set_aspect("equal")
plt.title(Title_2)
plt.sca(axs[3])
plt.title('@')
plt.axis('off')
plt.sca(axs[4])
ax = sns.heatmap(M3,cmap='RdYlBu_r',
vmin = Ranges[2][0],
vmax = Ranges[2][1],
cbar=False,
xticklabels=False,
yticklabels=False)
if Equal_tags[2] == True:
ax.set_aspect("equal")
plt.title(Title_3)
#%%
def plot_four_figs(X,v_j,idx):
# Fig 1: X@v_j = z_j
z_j = X@v_j
Titles = ['$X$',
'$v_' + str(idx) + '$',
'$z_' + str(idx) + '$']
Ranges = [[-2,11],
[-1,1],
[-2,11]]
Equal_tags = [False,True,False]
heatmap([X,v_j,z_j],Titles,Ranges,Equal_tags)
# Fig 2: z@v_j.T = X_j
X_j = z_j@v_j.T
Titles = ['$z_' + str(idx) + '$',
'$v_' + str(idx) + '^T$',
'$X_' + str(idx) + '$']
Ranges = [[-2,11],
[-1,1],
[-2,11]]
Equal_tags = [False,True,False]
heatmap([z_j,v_j.T,X_j],Titles,Ranges,Equal_tags)
# Fig 3: T_j = v_j@v_j.T
T_j = v_j@v_j.T
Titles = ['$v_' + str(idx) + '$',
'$v_' + str(idx) + '^T$',
'$T_' + str(idx) + '$']
Ranges = [[-1,1],
[-1,1],
[-1,1]]
Equal_tags = [True,True,True]
heatmap([v_j,v_j.T,T_j],Titles,Ranges,Equal_tags)
# Fig 4: X@T_j = X_j
T_j = X@T_j
Titles = ['$X$',
'$T_' + str(idx) + '$',
'$X_' + str(idx) + '$']
Ranges = [[-2,11],
[-1,1],
[-2,11]]
Equal_tags = [False,True,False]
heatmap([X,T_j,X_j],Titles,Ranges,Equal_tags)
#%% First basis vector
v1 = V[:, 0].reshape((-1, 1))
plot_four_figs(X,v1,1)
#%% Second basis vector
v2 = V[:, 1].reshape((-1, 1))
plot_four_figs(X,v2,2)
#%% Third basis vector
v3 = V[:, 2].reshape((-1, 1))
plot_four_figs(X,v3,3)
#%% Fourth basis vector
v4 = V[:, 3].reshape((-1, 1))
plot_four_figs(X,v4,4)