c@427: /* dtrmv.f -- translated by f2c (version 20061008).
c@427:    You must link the resulting object file with libf2c:
c@427: 	on Microsoft Windows system, link with libf2c.lib;
c@427: 	on Linux or Unix systems, link with .../path/to/libf2c.a -lm
c@427: 	or, if you install libf2c.a in a standard place, with -lf2c -lm
c@427: 	-- in that order, at the end of the command line, as in
c@427: 		cc *.o -lf2c -lm
c@427: 	Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
c@427: 
c@427: 		http://www.netlib.org/f2c/libf2c.zip
c@427: */
c@427: 
c@427: #include "f2c.h"
c@427: #include "blaswrap.h"
c@427: 
c@427: /* Subroutine */ int dtrmv_(char *uplo, char *trans, char *diag, integer *n, 
c@427: 	doublereal *a, integer *lda, doublereal *x, integer *incx)
c@427: {
c@427:     /* System generated locals */
c@427:     integer a_dim1, a_offset, i__1, i__2;
c@427: 
c@427:     /* Local variables */
c@427:     integer i__, j, ix, jx, kx, info;
c@427:     doublereal temp;
c@427:     extern logical lsame_(char *, char *);
c@427:     extern /* Subroutine */ int xerbla_(char *, integer *);
c@427:     logical nounit;
c@427: 
c@427: /*     .. Scalar Arguments .. */
c@427: /*     .. */
c@427: /*     .. Array Arguments .. */
c@427: /*     .. */
c@427: 
c@427: /*  Purpose */
c@427: /*  ======= */
c@427: 
c@427: /*  DTRMV  performs one of the matrix-vector operations */
c@427: 
c@427: /*     x := A*x,   or   x := A'*x, */
c@427: 
c@427: /*  where x is an n element vector and  A is an n by n unit, or non-unit, */
c@427: /*  upper or lower triangular matrix. */
c@427: 
c@427: /*  Arguments */
c@427: /*  ========== */
c@427: 
c@427: /*  UPLO   - CHARACTER*1. */
c@427: /*           On entry, UPLO specifies whether the matrix is an upper or */
c@427: /*           lower triangular matrix as follows: */
c@427: 
c@427: /*              UPLO = 'U' or 'u'   A is an upper triangular matrix. */
c@427: 
c@427: /*              UPLO = 'L' or 'l'   A is a lower triangular matrix. */
c@427: 
c@427: /*           Unchanged on exit. */
c@427: 
c@427: /*  TRANS  - CHARACTER*1. */
c@427: /*           On entry, TRANS specifies the operation to be performed as */
c@427: /*           follows: */
c@427: 
c@427: /*              TRANS = 'N' or 'n'   x := A*x. */
c@427: 
c@427: /*              TRANS = 'T' or 't'   x := A'*x. */
c@427: 
c@427: /*              TRANS = 'C' or 'c'   x := A'*x. */
c@427: 
c@427: /*           Unchanged on exit. */
c@427: 
c@427: /*  DIAG   - CHARACTER*1. */
c@427: /*           On entry, DIAG specifies whether or not A is unit */
c@427: /*           triangular as follows: */
c@427: 
c@427: /*              DIAG = 'U' or 'u'   A is assumed to be unit triangular. */
c@427: 
c@427: /*              DIAG = 'N' or 'n'   A is not assumed to be unit */
c@427: /*                                  triangular. */
c@427: 
c@427: /*           Unchanged on exit. */
c@427: 
c@427: /*  N      - INTEGER. */
c@427: /*           On entry, N specifies the order of the matrix A. */
c@427: /*           N must be at least zero. */
c@427: /*           Unchanged on exit. */
c@427: 
c@427: /*  A      - DOUBLE PRECISION array of DIMENSION ( LDA, n ). */
c@427: /*           Before entry with  UPLO = 'U' or 'u', the leading n by n */
c@427: /*           upper triangular part of the array A must contain the upper */
c@427: /*           triangular matrix and the strictly lower triangular part of */
c@427: /*           A is not referenced. */
c@427: /*           Before entry with UPLO = 'L' or 'l', the leading n by n */
c@427: /*           lower triangular part of the array A must contain the lower */
c@427: /*           triangular matrix and the strictly upper triangular part of */
c@427: /*           A is not referenced. */
c@427: /*           Note that when  DIAG = 'U' or 'u', the diagonal elements of */
c@427: /*           A are not referenced either, but are assumed to be unity. */
c@427: /*           Unchanged on exit. */
c@427: 
c@427: /*  LDA    - INTEGER. */
c@427: /*           On entry, LDA specifies the first dimension of A as declared */
c@427: /*           in the calling (sub) program. LDA must be at least */
c@427: /*           max( 1, n ). */
c@427: /*           Unchanged on exit. */
c@427: 
c@427: /*  X      - DOUBLE PRECISION array of dimension at least */
c@427: /*           ( 1 + ( n - 1 )*abs( INCX ) ). */
c@427: /*           Before entry, the incremented array X must contain the n */
c@427: /*           element vector x. On exit, X is overwritten with the */
c@427: /*           tranformed vector x. */
c@427: 
c@427: /*  INCX   - INTEGER. */
c@427: /*           On entry, INCX specifies the increment for the elements of */
c@427: /*           X. INCX must not be zero. */
c@427: /*           Unchanged on exit. */
c@427: 
c@427: 
c@427: /*  Level 2 Blas routine. */
c@427: 
c@427: /*  -- Written on 22-October-1986. */
c@427: /*     Jack Dongarra, Argonne National Lab. */
c@427: /*     Jeremy Du Croz, Nag Central Office. */
c@427: /*     Sven Hammarling, Nag Central Office. */
c@427: /*     Richard Hanson, Sandia National Labs. */
c@427: 
c@427: 
c@427: /*     .. Parameters .. */
c@427: /*     .. */
c@427: /*     .. Local Scalars .. */
c@427: /*     .. */
c@427: /*     .. External Functions .. */
c@427: /*     .. */
c@427: /*     .. External Subroutines .. */
c@427: /*     .. */
c@427: /*     .. Intrinsic Functions .. */
c@427: /*     .. */
c@427: 
c@427: /*     Test the input parameters. */
c@427: 
c@427:     /* Parameter adjustments */
c@427:     a_dim1 = *lda;
c@427:     a_offset = 1 + a_dim1;
c@427:     a -= a_offset;
c@427:     --x;
c@427: 
c@427:     /* Function Body */
c@427:     info = 0;
c@427:     if (! lsame_(uplo, "U") && ! lsame_(uplo, "L")) {
c@427: 	info = 1;
c@427:     } else if (! lsame_(trans, "N") && ! lsame_(trans, 
c@427: 	    "T") && ! lsame_(trans, "C")) {
c@427: 	info = 2;
c@427:     } else if (! lsame_(diag, "U") && ! lsame_(diag, 
c@427: 	    "N")) {
c@427: 	info = 3;
c@427:     } else if (*n < 0) {
c@427: 	info = 4;
c@427:     } else if (*lda < max(1,*n)) {
c@427: 	info = 6;
c@427:     } else if (*incx == 0) {
c@427: 	info = 8;
c@427:     }
c@427:     if (info != 0) {
c@427: 	xerbla_("DTRMV ", &info);
c@427: 	return 0;
c@427:     }
c@427: 
c@427: /*     Quick return if possible. */
c@427: 
c@427:     if (*n == 0) {
c@427: 	return 0;
c@427:     }
c@427: 
c@427:     nounit = lsame_(diag, "N");
c@427: 
c@427: /*     Set up the start point in X if the increment is not unity. This */
c@427: /*     will be  ( N - 1 )*INCX  too small for descending loops. */
c@427: 
c@427:     if (*incx <= 0) {
c@427: 	kx = 1 - (*n - 1) * *incx;
c@427:     } else if (*incx != 1) {
c@427: 	kx = 1;
c@427:     }
c@427: 
c@427: /*     Start the operations. In this version the elements of A are */
c@427: /*     accessed sequentially with one pass through A. */
c@427: 
c@427:     if (lsame_(trans, "N")) {
c@427: 
c@427: /*        Form  x := A*x. */
c@427: 
c@427: 	if (lsame_(uplo, "U")) {
c@427: 	    if (*incx == 1) {
c@427: 		i__1 = *n;
c@427: 		for (j = 1; j <= i__1; ++j) {
c@427: 		    if (x[j] != 0.) {
c@427: 			temp = x[j];
c@427: 			i__2 = j - 1;
c@427: 			for (i__ = 1; i__ <= i__2; ++i__) {
c@427: 			    x[i__] += temp * a[i__ + j * a_dim1];
c@427: /* L10: */
c@427: 			}
c@427: 			if (nounit) {
c@427: 			    x[j] *= a[j + j * a_dim1];
c@427: 			}
c@427: 		    }
c@427: /* L20: */
c@427: 		}
c@427: 	    } else {
c@427: 		jx = kx;
c@427: 		i__1 = *n;
c@427: 		for (j = 1; j <= i__1; ++j) {
c@427: 		    if (x[jx] != 0.) {
c@427: 			temp = x[jx];
c@427: 			ix = kx;
c@427: 			i__2 = j - 1;
c@427: 			for (i__ = 1; i__ <= i__2; ++i__) {
c@427: 			    x[ix] += temp * a[i__ + j * a_dim1];
c@427: 			    ix += *incx;
c@427: /* L30: */
c@427: 			}
c@427: 			if (nounit) {
c@427: 			    x[jx] *= a[j + j * a_dim1];
c@427: 			}
c@427: 		    }
c@427: 		    jx += *incx;
c@427: /* L40: */
c@427: 		}
c@427: 	    }
c@427: 	} else {
c@427: 	    if (*incx == 1) {
c@427: 		for (j = *n; j >= 1; --j) {
c@427: 		    if (x[j] != 0.) {
c@427: 			temp = x[j];
c@427: 			i__1 = j + 1;
c@427: 			for (i__ = *n; i__ >= i__1; --i__) {
c@427: 			    x[i__] += temp * a[i__ + j * a_dim1];
c@427: /* L50: */
c@427: 			}
c@427: 			if (nounit) {
c@427: 			    x[j] *= a[j + j * a_dim1];
c@427: 			}
c@427: 		    }
c@427: /* L60: */
c@427: 		}
c@427: 	    } else {
c@427: 		kx += (*n - 1) * *incx;
c@427: 		jx = kx;
c@427: 		for (j = *n; j >= 1; --j) {
c@427: 		    if (x[jx] != 0.) {
c@427: 			temp = x[jx];
c@427: 			ix = kx;
c@427: 			i__1 = j + 1;
c@427: 			for (i__ = *n; i__ >= i__1; --i__) {
c@427: 			    x[ix] += temp * a[i__ + j * a_dim1];
c@427: 			    ix -= *incx;
c@427: /* L70: */
c@427: 			}
c@427: 			if (nounit) {
c@427: 			    x[jx] *= a[j + j * a_dim1];
c@427: 			}
c@427: 		    }
c@427: 		    jx -= *incx;
c@427: /* L80: */
c@427: 		}
c@427: 	    }
c@427: 	}
c@427:     } else {
c@427: 
c@427: /*        Form  x := A'*x. */
c@427: 
c@427: 	if (lsame_(uplo, "U")) {
c@427: 	    if (*incx == 1) {
c@427: 		for (j = *n; j >= 1; --j) {
c@427: 		    temp = x[j];
c@427: 		    if (nounit) {
c@427: 			temp *= a[j + j * a_dim1];
c@427: 		    }
c@427: 		    for (i__ = j - 1; i__ >= 1; --i__) {
c@427: 			temp += a[i__ + j * a_dim1] * x[i__];
c@427: /* L90: */
c@427: 		    }
c@427: 		    x[j] = temp;
c@427: /* L100: */
c@427: 		}
c@427: 	    } else {
c@427: 		jx = kx + (*n - 1) * *incx;
c@427: 		for (j = *n; j >= 1; --j) {
c@427: 		    temp = x[jx];
c@427: 		    ix = jx;
c@427: 		    if (nounit) {
c@427: 			temp *= a[j + j * a_dim1];
c@427: 		    }
c@427: 		    for (i__ = j - 1; i__ >= 1; --i__) {
c@427: 			ix -= *incx;
c@427: 			temp += a[i__ + j * a_dim1] * x[ix];
c@427: /* L110: */
c@427: 		    }
c@427: 		    x[jx] = temp;
c@427: 		    jx -= *incx;
c@427: /* L120: */
c@427: 		}
c@427: 	    }
c@427: 	} else {
c@427: 	    if (*incx == 1) {
c@427: 		i__1 = *n;
c@427: 		for (j = 1; j <= i__1; ++j) {
c@427: 		    temp = x[j];
c@427: 		    if (nounit) {
c@427: 			temp *= a[j + j * a_dim1];
c@427: 		    }
c@427: 		    i__2 = *n;
c@427: 		    for (i__ = j + 1; i__ <= i__2; ++i__) {
c@427: 			temp += a[i__ + j * a_dim1] * x[i__];
c@427: /* L130: */
c@427: 		    }
c@427: 		    x[j] = temp;
c@427: /* L140: */
c@427: 		}
c@427: 	    } else {
c@427: 		jx = kx;
c@427: 		i__1 = *n;
c@427: 		for (j = 1; j <= i__1; ++j) {
c@427: 		    temp = x[jx];
c@427: 		    ix = jx;
c@427: 		    if (nounit) {
c@427: 			temp *= a[j + j * a_dim1];
c@427: 		    }
c@427: 		    i__2 = *n;
c@427: 		    for (i__ = j + 1; i__ <= i__2; ++i__) {
c@427: 			ix += *incx;
c@427: 			temp += a[i__ + j * a_dim1] * x[ix];
c@427: /* L150: */
c@427: 		    }
c@427: 		    x[jx] = temp;
c@427: 		    jx += *incx;
c@427: /* L160: */
c@427: 		}
c@427: 	    }
c@427: 	}
c@427:     }
c@427: 
c@427:     return 0;
c@427: 
c@427: /*     End of DTRMV . */
c@427: 
c@427: } /* dtrmv_ */