127 SUBROUTINE zpot06( UPLO, N, NRHS, A, LDA, X, LDX, B, LDB,
137 INTEGER lda, ldb, ldx, n, nrhs
138 DOUBLE PRECISION resid
141 DOUBLE PRECISION rwork( * )
142 COMPLEX*16 a( lda, * ),
b( ldb, * ), x( ldx, * )
148 DOUBLE PRECISION zero, one
149 parameter( zero = 0.0d+0, one = 1.0d+0 )
150 COMPLEX*16 cone, negcone
151 parameter( cone = ( 1.0d+0, 0.0d+0 ) )
152 parameter( negcone = ( -1.0d+0, 0.0d+0 ) )
156 DOUBLE PRECISION anorm, bnorm, eps, xnorm
169 INTRINSIC abs, dble, dimag, max
172 DOUBLE PRECISION cabs1
175 cabs1( zdum ) = abs( dble( zdum ) ) + abs( dimag( zdum ) )
182 IF( n.LE.0 .OR. nrhs.EQ.0 )
THEN
190 anorm =
zlansy(
'I', uplo, n, a, lda, rwork )
191 IF( anorm.LE.zero )
THEN
199 CALL
zhemm(
'Left', uplo, n, nrhs, negcone, a, lda, x,
200 $ ldx, cone,
b, ldb )
208 xnorm = cabs1(x(
izamax( n, x( 1,
j ), 1 ),
j))
209 IF( xnorm.LE.zero )
THEN
212 resid = max( resid, ( ( bnorm / anorm ) / xnorm ) / eps )
integer function izamax(N, ZX, INCX)
IZAMAX
double precision function zlansy(NORM, UPLO, N, A, LDA, WORK)
ZLANSY returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a complex symmetric matrix.
set ue cd $ADTTMP cat<< EOF > tmp f Program LinearEquations Implicit none Real b(3) integer i
logical function lsame(CA, CB)
LSAME
double precision function dlamch(CMACH)
DLAMCH
set ue cd $ADTTMP cat<< EOF > tmp f Program LinearEquations Implicit none Real j
subroutine zhemm(SIDE, UPLO, M, N, ALPHA, A, LDA, B, LDB, BETA, C, LDC)
ZHEMM
subroutine zpot06(UPLO, N, NRHS, A, LDA, X, LDX, B, LDB, RWORK, RESID)
ZPOT06