124 SUBROUTINE sgtt02( TRANS, N, NRHS, DL, D, DU, X, LDX, B, LDB,
134 INTEGER ldb, ldx, n, nrhs
138 REAL b( ldb, * ), d( * ), dl( * ), du( * ),
146 parameter( one = 1.0e+0, zero = 0.0e+0 )
150 REAL anorm, bnorm, eps, xnorm
168 IF( n.LE.0 .OR. nrhs.EQ.0 )
174 IF(
lsame( trans,
'N' ) )
THEN
175 anorm =
slangt(
'1', n, dl, d, du )
177 anorm =
slangt(
'I', n, dl, d, du )
183 IF( anorm.LE.zero )
THEN
190 CALL
slagtm( trans, n, nrhs, -one, dl, d, du, x, ldx, one,
b,
194 bnorm =
sasum( n,
b( 1,
j ), 1 )
195 xnorm =
sasum( n, x( 1,
j ), 1 )
196 IF( xnorm.LE.zero )
THEN
199 resid = max( resid, ( ( bnorm / anorm ) / xnorm ) / eps )
real function sasum(N, SX, INCX)
SASUM
set ue cd $ADTTMP cat<< EOF > tmp f Program LinearEquations Implicit none Real b(3) integer i
logical function lsame(CA, CB)
LSAME
real function slangt(NORM, N, DL, D, DU)
SLANGT returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value ...
real function slamch(CMACH)
SLAMCH
set ue cd $ADTTMP cat<< EOF > tmp f Program LinearEquations Implicit none Real j
subroutine sgtt02(TRANS, N, NRHS, DL, D, DU, X, LDX, B, LDB, RESID)
SGTT02
subroutine slagtm(TRANS, N, NRHS, ALPHA, DL, D, DU, X, LDX, BETA, B, LDB)
SLAGTM performs a matrix-matrix product of the form C = αAB+βC, where A is a tridiagonal matrix...