higham/matrix-inv-trig-hyp

This repository contains MATLAB functions to compute the matrix inverse cosine, matrix inverse sine, matrix hyperbolic inverse cosine, and matrix hyperbolic inverse sine.
The algorithm for the matrix cosine is based on Schur decomposition and Padé approximation. The algorithms for the other functions call that for the matrix cosine. The algorithms are from

M. Aprahamian and N. J. Higham, "Matrix Inverse Trigonometric and Inverse Hyperbolic Functions: Theory and Algorithms", MIMS EPrint 2016.4, Manchester Institute for Mathematical Sciences, The University of Manchester, UK, January 2016.