RADICAL Real specified roots of real array.

Y = RADICAL(X, N) returns the real roots of polynomials Y.^N - X .
Elements of N that correspond to negative elements of X must be odd
integers.
X and N must have the same dimensions unless one is a scalar.
A scalar can operate into anything.

See also realpow, nthroot

Example:
>> x = [-1 -64 81; 32 0 49; 0 1 0]; n = [3 3 4; 5 2 2; 0 0 inf];
>> radical(x,n)

ans =

-1 -4 3
2 0 7
NaN 1 1

RADICAL is a replacement for NTHROOT which is famous for bugs.