unwindm is a MATLAB function that computes the matrix unwinding function of a square matrix A.

Other program files are

• test_uwnindm: runs some simple tests for the unwindm function.
• unwind computes the scalar unwinding number.

U = unwindm(A) compute the matrix unwinding function U of the n-by-n matrix A.

The code was developed in MATLAB R2020b and works with versions back to at least R2017a.

• Mary Aprahamian and Nicholas J. Higham, The Matrix Unwinding Function, with an Application to Computing the Matrix Exponential, SIAM J. Matrix Anal. Appl. 35(1), 88–109, 2014.
• Nicholas J. Higham, Making Sense of Multivalued Matrix Functions with the Matrix Unwinding Function, 2014.

See license.txt for licensing information.