lu-methods {fastmatrix} | R Documentation |
Reconstruct the L, U, or X matrices from an LU object
Description
Returns the original matrix from which the object was constructed or the components of the factorization.
Usage
constructX(x)
extractL(x)
extractU(x)
Arguments
x |
object representing an LU factorization. This will typically have
come from a previous call to |
Value
constructX
returns \bold{X}
, the original matrix from which the lu
object was constructed (because of the pivoting the \bold{X}
matrix is not exactly
the product between \bold{L}
and \bold{U}
).
extractL
returns \bold{L}
. This may be pivoted.
extractU
returns \bold{U}
.
See Also
lu
.
Examples
a <- matrix(c(10,-3,5,-7,2,-1,0,6,5), ncol = 3)
z <- lu(a)
L <- extractL(z)
L
U <- extractU(z)
U
X <- constructX(z)
all(a == X)
[Package fastmatrix version 0.5-772 Index]