116 SUBROUTINE dsptrs( UPLO, N, NRHS, AP, IPIV, B, LDB, INFO )
125 INTEGER info, ldb, n, nrhs
129 DOUBLE PRECISION ap( * ),
b( ldb, * )
136 parameter( one = 1.0d+0 )
141 DOUBLE PRECISION ak, akm1, akm1k, bk, bkm1, denom
156 upper =
lsame( uplo,
'U' )
157 IF( .NOT.upper .AND. .NOT.
lsame( uplo,
'L' ) )
THEN
159 ELSE IF( n.LT.0 )
THEN
161 ELSE IF( nrhs.LT.0 )
THEN
163 ELSE IF( ldb.LT.max( 1, n ) )
THEN
167 CALL
xerbla(
'DSPTRS', -info )
173 IF( n.EQ.0 .OR. nrhs.EQ.0 )
186 kc = n*( n+1 ) / 2 + 1
195 IF( ipiv( k ).GT.0 )
THEN
203 $ CALL
dswap( nrhs,
b( k, 1 ), ldb,
b( kp, 1 ), ldb )
208 CALL
dger( k-1, nrhs, -one, ap( kc ), 1,
b( k, 1 ), ldb,
213 CALL
dscal( nrhs, one / ap( kc+k-1 ),
b( k, 1 ), ldb )
223 $ CALL
dswap( nrhs,
b( k-1, 1 ), ldb,
b( kp, 1 ), ldb )
228 CALL
dger( k-2, nrhs, -one, ap( kc ), 1,
b( k, 1 ), ldb,
230 CALL
dger( k-2, nrhs, -one, ap( kc-( k-1 ) ), 1,
231 $
b( k-1, 1 ), ldb,
b( 1, 1 ), ldb )
236 akm1 = ap( kc-1 ) / akm1k
237 ak = ap( kc+k-1 ) / akm1k
238 denom = akm1*ak - one
240 bkm1 =
b( k-1,
j ) / akm1k
241 bk =
b( k,
j ) / akm1k
242 b( k-1,
j ) = ( ak*bkm1-bk ) / denom
243 b( k,
j ) = ( akm1*bk-bkm1 ) / denom
266 IF( ipiv( k ).GT.0 )
THEN
273 CALL
dgemv(
'Transpose', k-1, nrhs, -one,
b, ldb, ap( kc ),
274 $ 1, one,
b( k, 1 ), ldb )
280 $ CALL
dswap( nrhs,
b( k, 1 ), ldb,
b( kp, 1 ), ldb )
290 CALL
dgemv(
'Transpose', k-1, nrhs, -one,
b, ldb, ap( kc ),
291 $ 1, one,
b( k, 1 ), ldb )
292 CALL
dgemv(
'Transpose', k-1, nrhs, -one,
b, ldb,
293 $ ap( kc+k ), 1, one,
b( k+1, 1 ), ldb )
299 $ CALL
dswap( nrhs,
b( k, 1 ), ldb,
b( kp, 1 ), ldb )
325 IF( ipiv( k ).GT.0 )
THEN
333 $ CALL
dswap( nrhs,
b( k, 1 ), ldb,
b( kp, 1 ), ldb )
339 $ CALL
dger( n-k, nrhs, -one, ap( kc+1 ), 1,
b( k, 1 ),
340 $ ldb,
b( k+1, 1 ), ldb )
344 CALL
dscal( nrhs, one / ap( kc ),
b( k, 1 ), ldb )
355 $ CALL
dswap( nrhs,
b( k+1, 1 ), ldb,
b( kp, 1 ), ldb )
361 CALL
dger( n-k-1, nrhs, -one, ap( kc+2 ), 1,
b( k, 1 ),
362 $ ldb,
b( k+2, 1 ), ldb )
363 CALL
dger( n-k-1, nrhs, -one, ap( kc+n-k+2 ), 1,
364 $
b( k+1, 1 ), ldb,
b( k+2, 1 ), ldb )
370 akm1 = ap( kc ) / akm1k
371 ak = ap( kc+n-k+1 ) / akm1k
372 denom = akm1*ak - one
374 bkm1 =
b( k,
j ) / akm1k
375 bk =
b( k+1,
j ) / akm1k
376 b( k,
j ) = ( ak*bkm1-bk ) / denom
377 b( k+1,
j ) = ( akm1*bk-bkm1 ) / denom
379 kc = kc + 2*( n-k ) + 1
392 kc = n*( n+1 ) / 2 + 1
401 IF( ipiv( k ).GT.0 )
THEN
409 $ CALL
dgemv(
'Transpose', n-k, nrhs, -one,
b( k+1, 1 ),
410 $ ldb, ap( kc+1 ), 1, one,
b( k, 1 ), ldb )
416 $ CALL
dswap( nrhs,
b( k, 1 ), ldb,
b( kp, 1 ), ldb )
426 CALL
dgemv(
'Transpose', n-k, nrhs, -one,
b( k+1, 1 ),
427 $ ldb, ap( kc+1 ), 1, one,
b( k, 1 ), ldb )
428 CALL
dgemv(
'Transpose', n-k, nrhs, -one,
b( k+1, 1 ),
429 $ ldb, ap( kc-( n-k ) ), 1, one,
b( k-1, 1 ),
437 $ CALL
dswap( nrhs,
b( k, 1 ), ldb,
b( kp, 1 ), ldb )
subroutine dger(M, N, ALPHA, X, INCX, Y, INCY, A, LDA)
DGER
LOGICAL function lsame(CA, CB)
LSAME
subroutine dsptrs(UPLO, N, NRHS, AP, IPIV, B, LDB, INFO)
DSPTRS
subroutine xerbla(SRNAME, INFO)
XERBLA
set ue cd $ADTTMP cat<< EOF > tmp f Program LinearEquations Implicit none Real b(3) integer i
subroutine dscal(N, DA, DX, INCX)
DSCAL
set ue cd $ADTTMP cat<< EOF > tmp f Program LinearEquations Implicit none Real j
subroutine dswap(N, DX, INCX, DY, INCY)
DSWAP
subroutine dgemv(TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)
DGEMV