165 SUBROUTINE sgtt05( TRANS, N, NRHS, DL, D, DU, B, LDB, X, LDX,
166 $ xact, ldxact, ferr, berr, reslts )
175 INTEGER ldb, ldx, ldxact, n, nrhs
178 REAL b( ldb, * ), berr( * ), d( * ), dl( * ),
179 $ du( * ), ferr( * ), reslts( * ),
x( ldx, * ),
187 parameter( zero = 0.0e+0, one = 1.0e+0 )
191 INTEGER i, imax,
j, k, nz
192 REAL axbi, diff, eps, errbnd, ovfl, tmp, unfl, xnorm
201 INTRINSIC abs, max, min
207 IF( n.LE.0 .OR. nrhs.LE.0 )
THEN
214 unfl =
slamch(
'Safe minimum' )
216 notran =
lsame( trans,
'N' )
226 xnorm = max( abs(
x( imax,
j ) ), unfl )
229 diff = max( diff, abs(
x( i,
j )-xact( i,
j ) ) )
232 IF( xnorm.GT.one )
THEN
234 ELSE IF( diff.LE.ovfl*xnorm )
THEN
242 IF( diff / xnorm.LE.ferr(
j ) )
THEN
243 errbnd = max( errbnd, ( diff / xnorm ) / ferr(
j ) )
256 axbi = abs(
b( 1, k ) ) + abs( d( 1 )*
x( 1, k ) )
258 axbi = abs(
b( 1, k ) ) + abs( d( 1 )*
x( 1, k ) ) +
259 $ abs( du( 1 )*
x( 2, k ) )
261 tmp = abs(
b( i, k ) ) + abs( dl( i-1 )*
x( i-1, k ) )
262 $ + abs( d( i )*
x( i, k ) ) +
263 $ abs( du( i )*
x( i+1, k ) )
264 axbi = min( axbi, tmp )
266 tmp = abs(
b( n, k ) ) + abs( dl( n-1 )*
x( n-1, k ) ) +
267 $ abs( d( n )*
x( n, k ) )
268 axbi = min( axbi, tmp )
272 axbi = abs(
b( 1, k ) ) + abs( d( 1 )*
x( 1, k ) )
274 axbi = abs(
b( 1, k ) ) + abs( d( 1 )*
x( 1, k ) ) +
275 $ abs( dl( 1 )*
x( 2, k ) )
277 tmp = abs(
b( i, k ) ) + abs( du( i-1 )*
x( i-1, k ) )
278 $ + abs( d( i )*
x( i, k ) ) +
279 $ abs( dl( i )*
x( i+1, k ) )
280 axbi = min( axbi, tmp )
282 tmp = abs(
b( n, k ) ) + abs( du( n-1 )*
x( n-1, k ) ) +
283 $ abs( d( n )*
x( n, k ) )
284 axbi = min( axbi, tmp )
287 tmp = berr( k ) / ( nz*eps+nz*unfl / max( axbi, nz*unfl ) )
291 reslts( 2 ) = max( reslts( 2 ), tmp )
LOGICAL function lsame(CA, CB)
LSAME
INTEGER function isamax(N, SX, INCX)
ISAMAX
subroutine sgtt05(TRANS, N, NRHS, DL, D, DU, B, LDB, X, LDX, XACT, LDXACT, FERR, BERR, RESLTS)
SGTT05
REAL function slamch(CMACH)
SLAMCH
set ue cd $ADTTMP cat<< EOF > tmp f Program LinearEquations Implicit none Real b(3) integer i
set ue cd $ADTTMP cat<< EOF > tmp f Program LinearEquations Implicit none Real j