[FIXED] Singleton array 1 cannot be considered a valid collection

Issue

I am trying to present the confusion matrix after deep learning model, but there is an error, how can I fix it?

Y_pred = model.predict(X_val)
Y_pred_classes = np.argmax(Y_pred,axis = 1) 
Y_true = np.argmax(y_val,axis = 0) 
confusion_mtx = confusion_matrix(Y_true, Y_pred_classes) 
f,ax = plt.subplots(figsize=(8, 8))
sns.heatmap(confusion_mtx, annot=True, linewidths=0.01,cmap="Greens",linecolor="gray", fmt= '.1f',ax=ax)
plt.xlabel("Predicted Label")
plt.ylabel("True Label")
plt.title("Confusion Matrix")
plt.show()

TypeError: Singleton array 1 cannot be considered a valid collection.

This is the output of Y_true and Y_pred_classes

Y_true

1

Y_pred_classes

array([0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0])

Solution

You need to remove this code #Y_true = np.argmax(y_val,axis = 0) as Y_true already carries actual label values, you need not to find the max probable number. You can directly use Y_true in confusion_matrix().

Please find below replicated and fixed code snippets:

Y_pred = model.predict(X_val)
Y_pred_classes = np.argmax(Y_pred,axis = 1) 

#Y_true = np.argmax(y_val,axis = 0) 

confusion_mtx = confusion_matrix(Y_true, Y_pred_classes) 
f,ax = plt.subplots(figsize=(8, 8))
sns.heatmap(confusion_mtx, annot=True, linewidths=0.01,cmap="Greens",linecolor="gray", fmt= '.1f',ax=ax)
plt.xlabel("Predicted Label")
plt.ylabel("True Label")
plt.title("Confusion Matrix")
plt.show()

Answered By - TFer2