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dla_gbrcond.3lapack

NAME

DLA_GBRCOND - DLA_GERCOND 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_GBRCOND( TRANS, N, KL, KU, AB, LDAB, AFB, LDAFB, IPIV, CMODE, C, INFO, WORK, IWORK )

    

IMPLICIT NONE

    

CHARACTER TRANS

    

INTEGER N, LDAB, LDAFB, INFO, KL, KU, CMODE

    

INTEGER IWORK( * ), IPIV( * )

    

DOUBLE PRECISION AB( LDAB, * ), AFB( LDAFB, * ), WORK( * ), C( * )

PURPOSE

   DLA_GERCOND 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 5*N.

IWORK integer workspace of size N.