How to randomized a n by m matrix ?

I want to randomize an n by m matrix containing numbers just between -1 to 1, where the sum of each row vector is equal to 1.

Ex. 3 by 2 matrix:

m = [.6 .3 .1; ...
     .2 .7 .1]

Answer 1

[Roger Stafford]

You can use my File Exchange routine “randfixedsum” at:

http://www.mathworks.com/matlabcentral/fileexchange/9700-random-vectors-with-fixed-sum

to obtain your 1 sums with values between -1 and 1.