confusion Matrix ,sensitivity and specificity

I have actual Y and prdicted Y matrix of 27×1 double type. i have written the following code but its not working. Kindly help me where i am wrong?

[cm,order] = confusionmat(actual_Y,predicted_Y);

% if yHat are your predictions and yval are your y true then

tp = sum((predicted_Y == 1) & (actual_Y == 1))

fp = sum((predicted_Y == 1) & (actual_Y == 0))

tn = sum((predicted_Y == 0) & (actual_Y == 1))

fn = sum((predicted_Y == 0) & (actual_Y == 0))

sensitivity = tp/(tp + fn) %TPR

specificity = tn/(tn + fp) %TNR

precision = tp / (tp + fp)

FPR = fp/(tn+fp);

Accuracy = (TP+TN)./(TP+FP+TN+FN);

recall = tp / (tp + fn)

F1 = (2 * precision * recall) / (precision + recall);

[Ameer Hamza]

What is not working? What is the error?

Answer 1

[Abdallah Ghazi Faisal Zaid Alkilani]

This line:

Accuracy = (TP+TN)./(TP+FP+TN+FN);

Is inconsistent with your variable names:

tp = sum((predicted_Y == 1) & (actual_Y == 1))
fp = sum((predicted_Y == 1) & (actual_Y == 0))
tn = sum((predicted_Y == 0) & (actual_Y == 1))
fn = sum((predicted_Y == 0) & (actual_Y == 0))

Pay closer attention to your variable names.

---------------------------------------------------------------

When I tried your code, I got this error:

Unrecognized function or variable 'TP'.

Error in Untitled (line 12)
Accuracy = (TP+TN)./(TP+FP+TN+FN);

Which means TP wasn't defined. After closer inspection, you will see that you should be using tp not TP. Same for the other variables in the statment above.

[Mina Kheirkhah Rahimabadi]

Just wanted to correct this in your code: tn = sum((predicted_Y == 0) & (actual_Y == 1))

This has to be 'fn' and the other one 'tn'