how to find accuracy from confusion matrix having 4 x4 dimensions

I have used the following function for finding confusion matrix c=confusionmat(x,y)

it gives me output like that ,

C =

0 4 0 0

0 0 0 0

0 0 0 0

0 0 4 0

now i want to find accuracy and f_measure from this confusion matrix

[Yasasvi Harish Kumar]

Hi,

Whats the function? Please include it.

[Rik]

The F-statistic is a different matter (a Google search should help you find a way to calculate that), but since there are no values on the diagonal, you can immediately see that the accuracy is 0.