91 REAL FUNCTION stzt02( M, N, AF, LDA, TAU, WORK,
100 INTEGER lda, lwork, m, n
103 REAL af( lda, * ), tau( * ), work( lwork )
110 parameter( zero = 0.0e0, one = 1.0e0 )
132 IF( lwork.LT.n*n+n )
THEN
133 CALL
xerbla(
'STZT02', 7 )
139 IF( m.LE.0 .OR. n.LE.0 )
144 CALL
slaset(
'Full', n, n, zero, one, work, n )
149 CALL
slatzm(
'Left', n-m+1, n, af( i, m+1 ), lda, tau( i ),
150 $ work( i ), work( m+1 ), n, work( n*n+1 ) )
156 CALL
slatzm(
'Left', n-m+1, n, af( i, m+1 ), lda, tau( i ),
157 $ work( i ), work( m+1 ), n, work( n*n+1 ) )
163 work( ( i-1 )*n+i ) = work( ( i-1 )*n+i ) - one
167 $ (
slamch(
'Epsilon' )*
REAL( MAX( M, N ) ) )
subroutine slaset(UPLO, M, N, ALPHA, BETA, A, LDA)
SLASET initializes the off-diagonal elements and the diagonal elements of a matrix to given values...
real function slange(NORM, M, N, A, LDA, WORK)
SLANGE returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value ...
subroutine xerbla(SRNAME, INFO)
XERBLA
real function slamch(CMACH)
SLAMCH
subroutine slatzm(SIDE, M, N, V, INCV, TAU, C1, C2, LDC, WORK)
SLATZM
real function stzt02(M, N, AF, LDA, TAU, WORK, LWORK)
STZT02