Null Spaces of Matrices

DESCRIPTION:

Given a matrix, M, find a matrix N giving a basis for the null space. That is t(N) %*% M is the zero and N has the maximum number of linearly independent columns.

USAGE:

Null(M)

REQUIRED ARGUMENTS:

M
Input matrix. A vector is coerced to a 1-column matrix.

VALUE:

The matrix N with the basis for the null space, or an empty vector if the matrix M is square and of maximal rank.

SEE ALSO:

,

EXAMPLES:

# The function is currently defined as
function(M)
{
        tmp <- qr(M)
        set <- if(tmp$rank == 0) 1:ncol(M) else  - (1:tmp$rank)
        qr.Q(tmp, complete = T)[, set, drop = F]
}