#confusion_matrix
import numpy as np
import matplotlib.pyplot as plt
classes = ['A','B','C','D','E']
confusion_matrix = np.array([(9,1,3,4,0),(2,13,1,3,4),(1,4,10,0,13),(3,1,1,17,0),(0,0,0,1,14)],dtype=np.float64)
plt.imshow(confusion_matrix, interpolation='nearest', cmap=plt.cm.Oranges) #按照像素显示出矩阵
plt.title('confusion_matrix')
plt.colorbar()
tick_marks = np.arange(len(classes))
plt.xticks(tick_marks, classes)
plt.yticks(tick_marks, classes)
thresh = confusion_matrix.max() / 2.
#iters = [[i,j] for i in range(len(classes)) for j in range((classes))]
#ij配对，遍历矩阵迭代器
iters = np.reshape([[[i,j] for j in range(5)] for i in range(5)],(confusion_matrix.size,2))
for i, j in iters:
plt.text(j, i, format(confusion_matrix[i, j])) #显示对应的数字
plt.ylabel('Real label')
plt.xlabel('Prediction')
plt.tight_layout()
plt.show()
from __future__ import division
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.ticker import MultipleLocator
def plotCM(classes, matrix, savname):
"""classes: a list of class names"""
# Normalize by row
matrix = matrix.astype(np.float)
linesum = matrix.sum(1)
linesum = np.dot(linesum.reshape(-1, 1), np.ones((1, matrix.shape[1])))
matrix /= linesum
# plot
plt.switch_backend('agg')
fig = plt.figure()
ax = fig.add_subplot(111)
cax = ax.matshow(matrix)
fig.colorbar(cax)
ax.xaxis.set_major_locator(MultipleLocator(1))
ax.yaxis.set_major_locator(MultipleLocator(1))
for i in range(matrix.shape[0]):
ax.text(i, i, str('%.2f' % (matrix[i, i] * 100)), va='center', ha='center')
ax.set_xticklabels([''] + classes, rotation=90)
ax.set_yticklabels([''] + classes)
#save
plt.savefig(savname)
