How to generate the first twenty powers of x?

Question

So, I\'ve got X, a 300-by-1 vector and I\'d like [1, X, X*X, X*X*X, ... , X*X*...*X], a 300-by-twenty matrix.

How should I do this?

X=[2;1]
[X,X.*X,X.*X         


        

Answer 1

Use bsxfun for a neat solution, or go for Luis Mendo's extravaganza to save some time ;)

powers = 1:20;
x = 1:20;

result = bsxfun(@power,x(:),powers(:).');    

gives:

 1    1    1 ...
 8   16   32 ...
27   81  243 ...
64  256 1024 ...
... ...  ...