IndexError: index 1 is out of bounds for axis 0 with size 1 - NumPy Python

Question

 for (i,j) in zip(Y_test,Y_pred_test):   
        if np.logical_and((Y_test[i]==1),(Y_pred_test[j]==1)):
            TP += 1                           
        elif np.logical_and((Y_test[i]==1),(Y_pred_test[j] == 0)):
            FN += 1                          
        elif np.logical_and((Y_test[i]==0),(Y_pred_test[j]==1)):
            FP += 1                           
        elif np.logical_and((Y_test[i]==0),(Y_pred_test[j]==0)):
            TN += 1

Python - NumPy Question:

I need help. My code keeps coming up with an error on this particular section. The error states "IndexError: index 1 is out of bounds for axis 0 with size 1"
I'm currently writing up how to Calculate TP, FP, TN, FN, Accuracy, Precision, Recall, and F-1 score.

Y_test data contains:

[[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
  0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1
  1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
  1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1]]

Y_pred_test data contains:

[[0. 0. 0. 0. 0. 1. 0. 0. 1. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 1. 0. 0. 1.
  0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 1. 1. 0. 1. 1. 0. 0. 0. 0. 0. 1. 0. 0.
  1. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 1. 0. 1. 1. 1. 1. 1. 1. 1. 0. 1. 1.
  1. 0. 1. 1. 1. 1. 1. 0. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
  1. 1. 1. 1. 0. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
  1. 1. 1. 1. 1.]]

Tls Chris · Accepted Answer · 2021-02-13 14:19:52Z

0

As Y_test and Y_pred_test are 2d arrays both i and j in the for loop are 1d arrays. Y_test[i] uses the values in i as the indices to access the rows in Y_test. Row zero exists but row 1 doesn't causing the error message.

import numpy as np
Y_test = np.array( [[ 0, 0, 0, 1, 1, 1, 1 ]] ) # Easy to see test data
Y_pred_test = np.array( [[ 0., 1., 1., 0., 0., 1. ]] ) 

for (i,j) in zip(Y_test,Y_pred_test):
     print(i,'\n', j) 

# [0 0 0 1 1 1 1]  # i in the loop 
# [0. 1. 1. 0. 0. 1.]   # j in the loop

edited Feb 13, 2021 at 14:19

answered Feb 13, 2021 at 14:11

Tls Chris

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1 Comment

iris0107 Over a year ago

thank you! I was able to fix my code with your guidance!

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