Data Coding

Confusion matrix from scratch

Mediumboolean maskssumbuilding arrays· 20 XP

A fraud model predicts 1 (fraud) or 0 (not fraud). An interviewer asks you to build the confusion matrix without any machine learning library. The labels are illustrative.

Store a 2 by 2 array laid out as [[TN, FP], [FN, TP]]:

  • TN: actual 0, predicted 0
  • FP: actual 0, predicted 1
  • FN: actual 1, predicted 0
  • TP: actual 1, predicted 1

Expected answer

Store your answer in result.

Hints, the later steps and the answer come with Pro.

import numpy as np

actual = np.array([0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0])
pred = np.array([0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0])
result = ...