Why do I receive an error when I use the NTHROOT function within MATLAB?

Question

MathWorks Support Team 2009-6-27

When I execute the following command:

r = nthroot(1,2)

I receive the following error message:

 ??? Error using ==> nthroot
 If X is negative, N must be an odd integer.

However, my value for X is not negative.

Answer 1

This bug has been fixed for Release 14 SP1 (R14SP1). For previous releases, read below for any possible workarounds:

This is a bug within MATLAB 7.0 (R14) in the NTHROOT function.

To work around this issue, perform the following steps.

1. In the MATLAB Command Window, type:

edit nthroot

2. Within the file that comes up in the MATLAB Editor/Debugger, replace line 17:

if any((x(:) < 0) & ((n(:) ~= fix(n(:)))) | rem(n,2)==0)

with the command:

if any((x(:) < 0) & (((n(:) ~= fix(n(:)))) | rem(n,2)==0))

3. Save the MATLAB file.