cofactor {matlib}

Cofactor of A[i,j]

Description

Returns the cofactor of element (i,j) of the square matrix A, i.e., the signed minor of the sub-matrix that results when row i and column j are deleted.

Usage

cofactor(A, i, j)

Arguments

A

a square matrix

i

row index

j

column index

Value

the cofactor of A[i,j]

Author(s)

Michael Friendly

See Also

rowCofactors for all cofactors of a given row

Other determinants: Det(), adjoint(), minor(), rowCofactors(), rowMinors()

Examples

M <- matrix(c(4, -12, -4,
              2,   1,  3,
             -1,  -3,  2), 3, 3, byrow=TRUE)
cofactor(M, 1, 1)
cofactor(M, 1, 2)
cofactor(M, 1, 3)