166 $ ipiv, cmode, c, info, work, iwork )
174 INTEGER n, ldab, ldafb, info, kl, ku, cmode
177 INTEGER iwork( * ), ipiv( * )
178 REAL ab( ldab, * ), afb( ldafb, * ), work( * ),
186 INTEGER kase, i, j, kd, ke
207 notrans =
lsame( trans,
'N' )
208 IF ( .NOT. notrans .AND. .NOT.
lsame(trans,
'T')
209 $ .AND. .NOT.
lsame(trans,
'C') )
THEN
211 ELSE IF( n.LT.0 )
THEN
213 ELSE IF( kl.LT.0 .OR. kl.GT.n-1 )
THEN
215 ELSE IF( ku.LT.0 .OR. ku.GT.n-1 )
THEN
217 ELSE IF( ldab.LT.kl+ku+1 )
THEN
219 ELSE IF( ldafb.LT.2*kl+ku+1 )
THEN
223 CALL xerbla(
'SLA_GBRCOND', -info )
239 IF ( cmode .EQ. 1 )
THEN
240 DO j = max( i-kl, 1 ), min( i+ku, n )
241 tmp = tmp + abs( ab( kd+i-j, j ) * c( j ) )
243 ELSE IF ( cmode .EQ. 0 )
THEN
244 DO j = max( i-kl, 1 ), min( i+ku, n )
245 tmp = tmp + abs( ab( kd+i-j, j ) )
248 DO j = max( i-kl, 1 ), min( i+ku, n )
249 tmp = tmp + abs( ab( kd+i-j, j ) / c( j ) )
257 IF ( cmode .EQ. 1 )
THEN
258 DO j = max( i-kl, 1 ), min( i+ku, n )
259 tmp = tmp + abs( ab( ke-i+j, i ) * c( j ) )
261 ELSE IF ( cmode .EQ. 0 )
THEN
262 DO j = max( i-kl, 1 ), min( i+ku, n )
263 tmp = tmp + abs( ab( ke-i+j, i ) )
266 DO j = max( i-kl, 1 ), min( i+ku, n )
267 tmp = tmp + abs( ab( ke-i+j, i ) / c( j ) )
280 CALL slacn2( n, work( n+1 ), work, iwork, ainvnm, kase, isave )
287 work( i ) = work( i ) * work( 2*n+i )
291 CALL sgbtrs(
'No transpose', n, kl, ku, 1, afb, ldafb,
292 $ ipiv, work, n, info )
294 CALL sgbtrs(
'Transpose', n, kl, ku, 1, afb, ldafb,
301 IF ( cmode .EQ. 1 )
THEN
303 work( i ) = work( i ) / c( i )
305 ELSE IF ( cmode .EQ. -1 )
THEN
307 work( i ) = work( i ) * c( i )
314 IF ( cmode .EQ. 1 )
THEN
316 work( i ) = work( i ) / c( i )
318 ELSE IF ( cmode .EQ. -1 )
THEN
320 work( i ) = work( i ) * c( i )
325 CALL sgbtrs(
'Transpose', n, kl, ku, 1, afb, ldafb,
329 CALL sgbtrs(
'No transpose', n, kl, ku, 1, afb, ldafb,
330 $ ipiv, work, n, info )
336 work( i ) = work( i ) * work( 2*n+i )
344 IF( ainvnm .NE. 0.0 )
real function sla_gbrcond(trans, n, kl, ku, ab, ldab, afb, ldafb, ipiv, cmode, c, info, work, iwork)
SLA_GBRCOND estimates the Skeel condition number for a general banded matrix.
subroutine slacn2(n, v, x, isgn, est, kase, isave)
SLACN2 estimates the 1-norm of a square matrix, using reverse communication for evaluating matrix-vec...