Display covariance;

imagesc(cov(data));

ROC using perfcurve :

[X,Y,T,AUC] = perfcurve(labels,scores,posclass)

Perf curve returns points on ROC curve. To obtain more robust results using multiple iteration; labels and scores should be cell array containing multiple iteration labels. In this case it returns Mx3 matrix for X , Y , AUC , first column represents the mean value and others are bounds.

Kernighan's law:

Debugging is twice as hard as the code first place. Therefore , if you write the code as cleverly as possible , by definition not smart enough to debug it .

I wonder if we can represent irrational number using some finite primitive irrational numbers + rational numbers like in complex numbers (i is primitive).