sla.qr {RScaLAPACK} | R Documentation |
The function sla.qr
computes the QR decomposition of a matrix using
the ScaLAPACK library routine PDGEQRF.
sla.qr(A, NPROWS=0, NPCOLS=0, MB=16, RFLAG = 1, SPAWN = 1 )
A |
A numeric matrix whose QR decomposition is to be computed. |
NPROWS |
Number of Process Rows in the Process Grid. |
NPCOLS |
Number of Process Cols in the Process Grid. |
MB |
Block Size. |
RFLAG |
Flag saying whether the Process Grid should be released after computation. |
SPAWN |
Flag saying whether a new Process Grid should be spawned. |
If the number of processor rows and columns are both zero, one processor is used. If the number of processor rows is nonzero and the number of processor columns is zero, then the processor rows is taken to be a number of processors, and a grid is made accordingly.
The QR decomposition of the matrix as computed by PDGEQRF is returned.
qr |
a matrix with the same dimensions as |
qraux |
a vector of length |
rank |
the length of vector \bold{qraux}. |
Nagiza Samatova (samatovan@ornl.gov), Guruprasad Kora (koragh@ornl.gov), Srikanth Yoginath (yoginathsb@ornl.gov), David Bauer (bauerda@ornl.gov)
http://mathworld.wolfram.com/QRDecomposition.html
http://www.netlib.org/scalapack/
qr
for the normal solving function.
library(RScaLAPACK) rnorm(10000)->x dim(x)=c(100,100) sla.qr(x, NPROWS=2,NPCOLS=2)