dla_syrcond3lapack
Dla_syrcond estimate the skeel condition number of op(a) * op2(c) where op2 is determined by cmode as follows cmode = 1 op2(c) = c cmode = 0 op2(c) = i cmode = -1 op2(c) = inv(c) the skeel condition number cond(a) = norminf( |inv(a)||a| ) is computed by computing scaling factors r such that diag(r)*a*op2(c) is row equilibrated and computing the standard infinity-norm condition number
Usage
- DOUBLE PRECISION
-
FUNCTION DLA_SYRCOND( UPLO, N, A, LDA, AF, LDAF, IPIV, CMODE, C, INFO, WORK, IWORK )
- IMPLICIT
-
NONE
- CHARACTER
-
UPLO
- INTEGER
-
N, LDA, LDAF, INFO, CMODE
- INTEGER
-
IWORK( * ), IPIV( * )
- DOUBLE
-
PRECISION A( LDA, * ), AF( LDAF, * ), WORK( * ), C( * )
Purpose
DLA_SYRCOND estimates the Skeel condition number of op(A) * op2(C)
where op2 is determined by CMODE as follows
CMODE = 1 op2(C) = C
CMODE = 0 op2(C) = I
CMODE = -1 op2(C) = inv(C)
The Skeel condition number cond(A) = norminf( |inv(A)||A| )
is computed by computing scaling factors R such that
diag(R)*A*op2(C) is row equilibrated and computing the standard
infinity-norm condition number.
Arguments
- WORK double precision workspace of size 3*N.
- IWORK integer workspace of size N.