isKerAinKerB: isKerAinKerB
In distrMod: Object Oriented Implementation of Probability Models

isKerAinKerB

R Documentation

isKerAinKerB

Description

For two matrices A and B checks whether the null space of A is a subspace of the null space of B, in other words, if Ax=0 entails Bx=0.

Usage

isKerAinKerB(A, B, tol = .Machine$double.eps)

Arguments

`A`	a matrix; if `A` is a vector, `A` is coerced to a matrix by `as.matrix`.
`B`	a matrix; if `B` is a vector, `B` is coerced to a matrix by `as.matrix`.
`tol`	the tolerance for detecting linear dependencies in the columns of `a` and up to which the two projectors are seen as equal (see below).

Details

via calls to svd, the projectors pi_A and pi_B onto the respective orthogonal complements of ker(A) and ker(B) are calculated and then is checked whether pi_B pi_A = pi_B.

Value

logical

Author(s)

Peter Ruckdeschel peter.ruckdeschel@uni-oldenburg.de

Examples

ma <- cbind(1,1,c(1,1,7))
D <- t(ma %*% c(0,1,-1))
## IGNORE_RDIFF_BEGIN
## note that results may vary according to BLAS
isKerAinKerB(D,ma)
isKerAinKerB(ma,D)
## IGNORE_RDIFF_END

distrMod documentation built on Nov. 16, 2022, 9:07 a.m.