inv_p {matrixmodp}

Calculate the inverse of a matrix mod p

Description

inv_p() finds the inverse of a square matrix over the field F_p. The function checks for invertibility and then row-reduces the augmented matrix [A|I] over F_p to find the inverse.

Usage

inv_p(A, p)

Arguments

A

A square matrix

p

A prime integer

Value

A square matrix of the same size as A

Examples

B <- matrix(c(5, 2, 3, 6, 5, 5, 4, 0, 2), 3, 3)
inv_p(B, 7)
C <- matrix(c(3, 0, 4, 0, 2, 1, 1, 3, 0, 3, 0, 1, 3, 0, 2, 1), 4, 4)
inv_p(C, 5)