Question

How to calculate precision of for positive and negative class separately?

Answer 1

Answer:

Step-by-step explanation:

Hi you have to divide results into four groups -

True class A (TA) - correctly classified into class A

False class A (FA) - incorrectly classified into class A

True class B (TB) - correctly classified into class B

False class B (FB) - incorrectly classified into class B

precision = TA / (TA + FA)

recall = TA / (TA + FB)

You might also need accuracy and F-measure:

accuracy = (TA + TB) / (TA + TB + FA + FB)

f-measure = 2 * ((precision * recall)/(precision + recall))

Answer 2

Step-by-step explanation:

The second statement should say that the determinant of an orthogonal matrix is ±1 and not the eigenvalues themselves. R is an orthogonal matrix, but its eigenvalues are e±i. The eigenvalues of an orthogonal matrix needs to have modulus one. If the eigenvalues happen to be real, then they are forced to be ±1.