Trigonometric/hyperbolic functions of square matrix x.
mode must be the name of a function. Valid functions are ’sin’, ’cos’, ’tan’, ’sec’, ’csc’, ’cot’ and all their inverses and/or hyperbolic variants, and ’sqrt’, ’log’ and ’exp’.
The code thfm (x, 'cos')
calculates matrix cosinus even if input
matrix x is not diagonalizable.
Important note:
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.
See also: funm.
Package: linear-algebra