coffg

Arguments

M

square matrix of numbers or polynomials or rationals, with real or complex coefficients.

tC

square matrix of the type of M: Transposed co-matrix of M, such that tC/d is equal to inv(M).

d

scalar: determinant det(M), with the M's data type and encoding.

Description

coffg(M) computes co-factors of M, and returns the transposed co-matrix tC.

When M has a single component, tC is 1 and d==M

For large matrices, calculations may be slow.

Examples

// With polynomials
a = [ %s, %s^2+1; %s  %s^2-1];
[a1, d] = coffg(a)
(a1/d) - inv(a)

// With rationals
a = [%s 0 ; 0 1/%s]
[a1, d] = coffg(a)
(a1/d) - inv(a)

See also

• inv — matrix inverse
• invr — inverts a matrix of polynomials or of rationals
• glever — inverse of matrix pencil
• determ — determinant of a matrix of polynomials
• detr — determinant of a matrix of rationals