NAME¶

DLA_SYRCOND - 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

SYNOPSIS¶

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.