diff options
Diffstat (limited to 'eigen/blas/dtbmv.f')
| -rw-r--r-- | eigen/blas/dtbmv.f | 335 |
1 files changed, 0 insertions, 335 deletions
diff --git a/eigen/blas/dtbmv.f b/eigen/blas/dtbmv.f deleted file mode 100644 index a87ffde..0000000 --- a/eigen/blas/dtbmv.f +++ /dev/null @@ -1,335 +0,0 @@ - SUBROUTINE DTBMV(UPLO,TRANS,DIAG,N,K,A,LDA,X,INCX) -* .. Scalar Arguments .. - INTEGER INCX,K,LDA,N - CHARACTER DIAG,TRANS,UPLO -* .. -* .. Array Arguments .. - DOUBLE PRECISION A(LDA,*),X(*) -* .. -* -* Purpose -* ======= -* -* DTBMV performs one of the matrix-vector operations -* -* x := A*x, or x := A'*x, -* -* where x is an n element vector and A is an n by n unit, or non-unit, -* upper or lower triangular band matrix, with ( k + 1 ) diagonals. -* -* Arguments -* ========== -* -* UPLO - CHARACTER*1. -* On entry, UPLO specifies whether the matrix is an upper or -* lower triangular matrix as follows: -* -* UPLO = 'U' or 'u' A is an upper triangular matrix. -* -* UPLO = 'L' or 'l' A is a lower triangular matrix. -* -* Unchanged on exit. -* -* TRANS - CHARACTER*1. -* On entry, TRANS specifies the operation to be performed as -* follows: -* -* TRANS = 'N' or 'n' x := A*x. -* -* TRANS = 'T' or 't' x := A'*x. -* -* TRANS = 'C' or 'c' x := A'*x. -* -* Unchanged on exit. -* -* DIAG - CHARACTER*1. -* On entry, DIAG specifies whether or not A is unit -* triangular as follows: -* -* DIAG = 'U' or 'u' A is assumed to be unit triangular. -* -* DIAG = 'N' or 'n' A is not assumed to be unit -* triangular. -* -* Unchanged on exit. -* -* N - INTEGER. -* On entry, N specifies the order of the matrix A. -* N must be at least zero. -* Unchanged on exit. -* -* K - INTEGER. -* On entry with UPLO = 'U' or 'u', K specifies the number of -* super-diagonals of the matrix A. -* On entry with UPLO = 'L' or 'l', K specifies the number of -* sub-diagonals of the matrix A. -* K must satisfy 0 .le. K. -* Unchanged on exit. -* -* A - DOUBLE PRECISION array of DIMENSION ( LDA, n ). -* Before entry with UPLO = 'U' or 'u', the leading ( k + 1 ) -* by n part of the array A must contain the upper triangular -* band part of the matrix of coefficients, supplied column by -* column, with the leading diagonal of the matrix in row -* ( k + 1 ) of the array, the first super-diagonal starting at -* position 2 in row k, and so on. The top left k by k triangle -* of the array A is not referenced. -* The following program segment will transfer an upper -* triangular band matrix from conventional full matrix storage -* to band storage: -* -* DO 20, J = 1, N -* M = K + 1 - J -* DO 10, I = MAX( 1, J - K ), J -* A( M + I, J ) = matrix( I, J ) -* 10 CONTINUE -* 20 CONTINUE -* -* Before entry with UPLO = 'L' or 'l', the leading ( k + 1 ) -* by n part of the array A must contain the lower triangular -* band part of the matrix of coefficients, supplied column by -* column, with the leading diagonal of the matrix in row 1 of -* the array, the first sub-diagonal starting at position 1 in -* row 2, and so on. The bottom right k by k triangle of the -* array A is not referenced. -* The following program segment will transfer a lower -* triangular band matrix from conventional full matrix storage -* to band storage: -* -* DO 20, J = 1, N -* M = 1 - J -* DO 10, I = J, MIN( N, J + K ) -* A( M + I, J ) = matrix( I, J ) -* 10 CONTINUE -* 20 CONTINUE -* -* Note that when DIAG = 'U' or 'u' the elements of the array A -* corresponding to the diagonal elements of the matrix are not -* referenced, but are assumed to be unity. -* Unchanged on exit. -* -* LDA - INTEGER. -* On entry, LDA specifies the first dimension of A as declared -* in the calling (sub) program. LDA must be at least -* ( k + 1 ). -* Unchanged on exit. -* -* X - DOUBLE PRECISION array of dimension at least -* ( 1 + ( n - 1 )*abs( INCX ) ). -* Before entry, the incremented array X must contain the n -* element vector x. On exit, X is overwritten with the -* tranformed vector x. -* -* INCX - INTEGER. -* On entry, INCX specifies the increment for the elements of -* X. INCX must not be zero. -* Unchanged on exit. -* -* Further Details -* =============== -* -* Level 2 Blas routine. -* -* -- Written on 22-October-1986. -* Jack Dongarra, Argonne National Lab. -* Jeremy Du Croz, Nag Central Office. -* Sven Hammarling, Nag Central Office. -* Richard Hanson, Sandia National Labs. -* -* ===================================================================== -* -* .. Parameters .. - DOUBLE PRECISION ZERO - PARAMETER (ZERO=0.0D+0) -* .. -* .. Local Scalars .. - DOUBLE PRECISION TEMP - INTEGER I,INFO,IX,J,JX,KPLUS1,KX,L - LOGICAL NOUNIT -* .. -* .. External Functions .. - LOGICAL LSAME - EXTERNAL LSAME -* .. -* .. External Subroutines .. - EXTERNAL XERBLA -* .. -* .. Intrinsic Functions .. - INTRINSIC MAX,MIN -* .. -* -* Test the input parameters. -* - INFO = 0 - IF (.NOT.LSAME(UPLO,'U') .AND. .NOT.LSAME(UPLO,'L')) THEN - INFO = 1 - ELSE IF (.NOT.LSAME(TRANS,'N') .AND. .NOT.LSAME(TRANS,'T') .AND. - + .NOT.LSAME(TRANS,'C')) THEN - INFO = 2 - ELSE IF (.NOT.LSAME(DIAG,'U') .AND. .NOT.LSAME(DIAG,'N')) THEN - INFO = 3 - ELSE IF (N.LT.0) THEN - INFO = 4 - ELSE IF (K.LT.0) THEN - INFO = 5 - ELSE IF (LDA.LT. (K+1)) THEN - INFO = 7 - ELSE IF (INCX.EQ.0) THEN - INFO = 9 - END IF - IF (INFO.NE.0) THEN - CALL XERBLA('DTBMV ',INFO) - RETURN - END IF -* -* Quick return if possible. -* - IF (N.EQ.0) RETURN -* - NOUNIT = LSAME(DIAG,'N') -* -* Set up the start point in X if the increment is not unity. This -* will be ( N - 1 )*INCX too small for descending loops. -* - IF (INCX.LE.0) THEN - KX = 1 - (N-1)*INCX - ELSE IF (INCX.NE.1) THEN - KX = 1 - END IF -* -* Start the operations. In this version the elements of A are -* accessed sequentially with one pass through A. -* - IF (LSAME(TRANS,'N')) THEN -* -* Form x := A*x. -* - IF (LSAME(UPLO,'U')) THEN - KPLUS1 = K + 1 - IF (INCX.EQ.1) THEN - DO 20 J = 1,N - IF (X(J).NE.ZERO) THEN - TEMP = X(J) - L = KPLUS1 - J - DO 10 I = MAX(1,J-K),J - 1 - X(I) = X(I) + TEMP*A(L+I,J) - 10 CONTINUE - IF (NOUNIT) X(J) = X(J)*A(KPLUS1,J) - END IF - 20 CONTINUE - ELSE - JX = KX - DO 40 J = 1,N - IF (X(JX).NE.ZERO) THEN - TEMP = X(JX) - IX = KX - L = KPLUS1 - J - DO 30 I = MAX(1,J-K),J - 1 - X(IX) = X(IX) + TEMP*A(L+I,J) - IX = IX + INCX - 30 CONTINUE - IF (NOUNIT) X(JX) = X(JX)*A(KPLUS1,J) - END IF - JX = JX + INCX - IF (J.GT.K) KX = KX + INCX - 40 CONTINUE - END IF - ELSE - IF (INCX.EQ.1) THEN - DO 60 J = N,1,-1 - IF (X(J).NE.ZERO) THEN - TEMP = X(J) - L = 1 - J - DO 50 I = MIN(N,J+K),J + 1,-1 - X(I) = X(I) + TEMP*A(L+I,J) - 50 CONTINUE - IF (NOUNIT) X(J) = X(J)*A(1,J) - END IF - 60 CONTINUE - ELSE - KX = KX + (N-1)*INCX - JX = KX - DO 80 J = N,1,-1 - IF (X(JX).NE.ZERO) THEN - TEMP = X(JX) - IX = KX - L = 1 - J - DO 70 I = MIN(N,J+K),J + 1,-1 - X(IX) = X(IX) + TEMP*A(L+I,J) - IX = IX - INCX - 70 CONTINUE - IF (NOUNIT) X(JX) = X(JX)*A(1,J) - END IF - JX = JX - INCX - IF ((N-J).GE.K) KX = KX - INCX - 80 CONTINUE - END IF - END IF - ELSE -* -* Form x := A'*x. -* - IF (LSAME(UPLO,'U')) THEN - KPLUS1 = K + 1 - IF (INCX.EQ.1) THEN - DO 100 J = N,1,-1 - TEMP = X(J) - L = KPLUS1 - J - IF (NOUNIT) TEMP = TEMP*A(KPLUS1,J) - DO 90 I = J - 1,MAX(1,J-K),-1 - TEMP = TEMP + A(L+I,J)*X(I) - 90 CONTINUE - X(J) = TEMP - 100 CONTINUE - ELSE - KX = KX + (N-1)*INCX - JX = KX - DO 120 J = N,1,-1 - TEMP = X(JX) - KX = KX - INCX - IX = KX - L = KPLUS1 - J - IF (NOUNIT) TEMP = TEMP*A(KPLUS1,J) - DO 110 I = J - 1,MAX(1,J-K),-1 - TEMP = TEMP + A(L+I,J)*X(IX) - IX = IX - INCX - 110 CONTINUE - X(JX) = TEMP - JX = JX - INCX - 120 CONTINUE - END IF - ELSE - IF (INCX.EQ.1) THEN - DO 140 J = 1,N - TEMP = X(J) - L = 1 - J - IF (NOUNIT) TEMP = TEMP*A(1,J) - DO 130 I = J + 1,MIN(N,J+K) - TEMP = TEMP + A(L+I,J)*X(I) - 130 CONTINUE - X(J) = TEMP - 140 CONTINUE - ELSE - JX = KX - DO 160 J = 1,N - TEMP = X(JX) - KX = KX + INCX - IX = KX - L = 1 - J - IF (NOUNIT) TEMP = TEMP*A(1,J) - DO 150 I = J + 1,MIN(N,J+K) - TEMP = TEMP + A(L+I,J)*X(IX) - IX = IX + INCX - 150 CONTINUE - X(JX) = TEMP - JX = JX + INCX - 160 CONTINUE - END IF - END IF - END IF -* - RETURN -* -* End of DTBMV . -* - END |