105 SUBROUTINE sptt02( N, NRHS, D, E, X, LDX, B, LDB, RESID )
113 INTEGER ldb, ldx, n, nrhs
117 REAL b( ldb, * ), d( * ), e( * ), x( ldx, * )
124 parameter( one = 1.0e+0, zero = 0.0e+0 )
128 REAL anorm, bnorm, eps, xnorm
151 anorm =
slanst(
'1', n, d, e )
156 IF( anorm.LE.zero )
THEN
163 CALL
slaptm( n, nrhs, -one, d, e, x, ldx, one,
b, ldb )
170 bnorm =
sasum( n,
b( 1,
j ), 1 )
171 xnorm =
sasum( n, x( 1,
j ), 1 )
172 IF( xnorm.LE.zero )
THEN
175 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
subroutine sptt02(N, NRHS, D, E, X, LDX, B, LDB, RESID)
SPTT02
real function slanst(NORM, N, D, E)
SLANST returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a real symmetric tridiagonal matrix.
real function slamch(CMACH)
SLAMCH
set ue cd $ADTTMP cat<< EOF > tmp f Program LinearEquations Implicit none Real j
subroutine slaptm(N, NRHS, ALPHA, D, E, X, LDX, BETA, B, LDB)
SLAPTM