Robert Dickson

Good help with a reference. It works when the direct alternative expression fails. But there are other (faster) alternatives that should be as accurate. Off hand, its not at all obvious to me why maxstar is better. (Perhaps if I've read the reference.)

x = randn(1,100)*100000;

tic,r1=log(sum(exp(x(:))));toc
Elapsed time is 0.000178 seconds.

tic,r2=maxstar(x);toc
Elapsed time is 0.017096 seconds.

tic,M=max(x(:));r3=M+log(sum(exp(sort(x(:))/M)));toc
Elapsed time is 0.000342 seconds.

[r1,r2,r3]
ans =
          Inf 2.7718e+05 2.7718e+05

Its also arguable that this should have a similar syntax to most other matlab operators with similar functionality. It should operate on a specified dimension. (See help for mean, max, etc.)