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@mesquita
Last active July 26, 2024 13:52
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Nice Confusion Matrix with percentage cbar
from matplotlib.ticker import PercentFormatter
import matplotlib.pyplot as plt
import seaborn as sns
from sklearn.metrics import confusion_matrix
def cm_analysis(y_true, y_pred, filename, labels, classes, ymap=None, figsize=(17,17)):
"""
Generate matrix plot of confusion matrix with pretty annotations.
The plot image is saved to disk.
args:
y_true: true label of the data, with shape (nsamples,)
y_pred: prediction of the data, with shape (nsamples,)
filename: filename of figure file to save
labels: string array, name the order of class labels in the confusion matrix.
use `clf.classes_` if using scikit-learn models.
with shape (nclass,).
classes: aliases for the labels. String array to be shown in the cm plot.
ymap: dict: any -> string, length == nclass.
if not None, map the labels & ys to more understandable strings.
Caution: original y_true, y_pred and labels must align.
figsize: the size of the figure plotted.
"""
sns.set(font_scale=2.8)
if ymap is not None:
y_pred = [ymap[yi] for yi in y_pred]
y_true = [ymap[yi] for yi in y_true]
labels = [ymap[yi] for yi in labels]
cm = confusion_matrix(y_true, y_pred, labels=labels)
cm_sum = np.sum(cm, axis=1, keepdims=True)
cm_perc = cm / cm_sum.astype(float) * 100
annot = np.empty_like(cm).astype(str)
nrows, ncols = cm.shape
for i in range(nrows):
for j in range(ncols):
c = cm[i, j]
p = cm_perc[i, j]
if i == j:
s = cm_sum[i]
annot[i, j] = '%.2f%%\n%d/%d' % (p, c, s)
#elif c == 0:
# annot[i, j] = ''
else:
annot[i, j] = '%.2f%%\n%d' % (p, c)
cm = confusion_matrix(y_true, y_pred, labels=labels, normalize='true')
cm = pd.DataFrame(cm, index=labels, columns=labels)
cm = cm * 100
cm.index.name = 'True Label'
cm.columns.name = 'Predicted Label'
fig, ax = plt.subplots(figsize=figsize)
plt.yticks(va='center')
sns.heatmap(cm, annot=annot, fmt='', ax=ax, xticklabels=classes, cbar=True, cbar_kws={'format':PercentFormatter()}, yticklabels=classes, cmap="Blues")
plt.savefig(filename, bbox_inches='tight')
@mesquita
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mesquita commented Sep 9, 2020

cf_setup4_nn

@pingaowang
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Super !! Thanks a lot!!

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