Y = funm(X,'function')
funm
evaluates general matrix functions. For any square matrix argument X
, funm(X,'function')
evaluates the matrix function specified by function
using Parlett's method [1].
funm(X,'sqrt')
and funm(X,'log')
are equivalent to sqrtm(X)
and logm(X)
. funm(X,'exp')
and expm(X)
compute the same function, but by different algorithms. expm(X)
is preferred.
produce the same results to within roundoff error asS = funm(X,'sin');
C = funm(X,'cos');
In either case, the results satisfyE = expm(i*X);
C = real(E);
S = imag(E);
S*S+C*C = I
where I = eye(size(X))
expm
,logm
,sqrtm
[2] C. B. Moler and C. F. Van Loan, "Nineteen Dubious Ways to Compute the Exponential of a Matrix," SIAM Review 20, pp. 801-836, 1979.
(c) Copyright 1994 by The MathWorks, Inc.