139 SUBROUTINE stzrqf( M, N, A, LDA, TAU, INFO )
147 INTEGER INFO, LDA, M, N
150 REAL A( lda, * ), TAU( * )
157 parameter ( one = 1.0e+0, zero = 0.0e+0 )
175 ELSE IF( n.LT.m )
THEN
177 ELSE IF( lda.LT.max( 1, m ) )
THEN
181 CALL xerbla(
'STZRQF', -info )
200 CALL slarfg( n-m+1, a( k, k ), a( k, m1 ), lda, tau( k ) )
202 IF( ( tau( k ).NE.zero ) .AND. ( k.GT.1 ) )
THEN
211 CALL scopy( k-1, a( 1, k ), 1, tau, 1 )
215 CALL sgemv(
'No transpose', k-1, n-m, one, a( 1, m1 ),
216 $ lda, a( k, m1 ), lda, one, tau, 1 )
221 CALL saxpy( k-1, -tau( k ), tau, 1, a( 1, k ), 1 )
222 CALL sger( k-1, n-m, -tau( k ), tau, 1, a( k, m1 ), lda,
subroutine sger(M, N, ALPHA, X, INCX, Y, INCY, A, LDA)
SGER
subroutine sgemv(TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)
SGEMV
subroutine stzrqf(M, N, A, LDA, TAU, INFO)
STZRQF
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine saxpy(N, SA, SX, INCX, SY, INCY)
SAXPY
subroutine slarfg(N, ALPHA, X, INCX, TAU)
SLARFG generates an elementary reflector (Householder matrix).
subroutine scopy(N, SX, INCX, SY, INCY)
SCOPY