for e.g. I have X =[20,5}. Basically i have 5 data sets stacked up. Can do something like [p] = wblfit(X)... and p should contain the parameters for each column of data. p(1) = [a1,b1]; p(2)=[a(2),b(2)]; I can do this the long hand way using for loop but i would like to do it in one go without a for loop. Note: In my actual case I have a huge matrix and I would like to save cpu time by somehow using matrix operations rather than for loop operation. Hence my question. Thanks in advance for help.