logm

Arguments

x

square matrix

Description

logm(x) is the matrix logarithm of x. The result is complex if x is not positive or definite positive. If x is a symmetric matrix, then calculation is made by Schur form. Otherwise, x is assumed diagonalizable. One has expm(logm(x))=x.

Examples

A=[1,2;3,4];
logm(A)
expm(logm(A))

A1=A*A';
logm(A1)
expm(logm(A1))

A1(1,1)=%i;
expm(logm(A1))

See also

• expm — square matrix exponential
• log — natural logarithm