thfm

USAGE  y = thfm ( x, MODE )

       trigonometric/hyperbolic functions of square matrix x

MODE    cos   sin   tan   sec   csc   cot
    cosh  sinh  tanh  sech  csch  coth
       acos  asin  atan  asec  acsc  acot
       acosh asinh atanh asech acsch acoth
       sqrt  log   exp

NOTE        --- IMPORTANT ---
    This algorithm does  NOT USE an eigensystem
    similarity transformation. It maps the MODE
    functions to functions of expm, logm and sqrtm, 
       which are known to be robust with respect to
    non-diagonalizable ('defective') x

EXA    thfm( x ,'cos' )  calculates  matrix cosinus
    EVEN IF input matrix x IS NOT DIAGONALIZABLE

ASSOC    expm, sqrtm, logm, funm
 Copyright    (C) 2001 Rolf Fabian <fabian@tu-cottbus.de>
 010213
    published under current GNU GENERAL PUBLIC LICENSE