111 SUBROUTINE ctrti2( UPLO, DIAG, N, A, LDA, INFO )
130 parameter ( one = ( 1.0e+0, 0.0e+0 ) )
133 LOGICAL NOUNIT, UPPER
152 upper = lsame( uplo,
'U' )
153 nounit = lsame( diag,
'N' )
154 IF( .NOT.upper .AND. .NOT.lsame( uplo,
'L' ) )
THEN
156 ELSE IF( .NOT.nounit .AND. .NOT.lsame( diag,
'U' ) )
THEN
158 ELSE IF( n.LT.0 )
THEN
160 ELSE IF( lda.LT.max( 1, n ) )
THEN
164 CALL xerbla(
'CTRTI2', -info )
174 a( j, j ) = one / a( j, j )
182 CALL ctrmv(
'Upper',
'No transpose', diag, j-1, a, lda,
184 CALL cscal( j-1, ajj, a( 1, j ), 1 )
192 a( j, j ) = one / a( j, j )
201 CALL ctrmv(
'Lower',
'No transpose', diag, n-j,
202 $ a( j+1, j+1 ), lda, a( j+1, j ), 1 )
203 CALL cscal( n-j, ajj, a( j+1, j ), 1 )
subroutine ctrti2(UPLO, DIAG, N, A, LDA, INFO)
CTRTI2 computes the inverse of a triangular matrix (unblocked algorithm).
subroutine cscal(N, CA, CX, INCX)
CSCAL
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine ctrmv(UPLO, TRANS, DIAG, N, A, LDA, X, INCX)
CTRMV