/*  -- translated by f2c (version 20240504).
   You must link the resulting object file with libf2c:
	on Microsoft Windows system, link with libf2c.lib;
	on Linux or Unix systems, link with .../path/to/libf2c.a -lm
	or, if you install libf2c.a in a standard place, with -lf2c -lm
	-- in that order, at the end of the command line, as in
		cc *.o -lf2c -lm
	Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,

		http://www.netlib.org/f2c/libf2c.zip
*/

#include "f2c.h"

/* > \brief \b DLASR applies a sequence of plane rotations to a general rectangular matrix.   

    =========== DOCUMENTATION ===========   

   Online html documentation available at   
              http://www.netlib.org/lapack/explore-html/   

   > \htmlonly   
   > Download DLASR + dependencies   
   > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlasr.f
">   
   > [TGZ]</a>   
   > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlasr.f
">   
   > [ZIP]</a>   
   > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlasr.f
">   
   > [TXT]</a>   
   > \endhtmlonly   

    Definition:   
    ===========   

         SUBROUTINE DLASR( SIDE, PIVOT, DIRECT, M, N, C, S, A, LDA )   

         CHARACTER          DIRECT, PIVOT, SIDE   
         INTEGER            LDA, M, N   
         DOUBLE PRECISION   A( LDA, * ), C( * ), S( * )   


   > \par Purpose:   
    =============   
   >   
   > \verbatim   
   >   
   > DLASR applies a sequence of plane rotations to a real matrix A,   
   > from either the left or the right.   
   >   
   > When SIDE = 'L', the transformation takes the form   
   >   
   >    A := P*A   
   >   
   > and when SIDE = 'R', the transformation takes the form   
   >   
   >    A := A*P**T   
   >   
   > where P is an orthogonal matrix consisting of a sequence of z plane   
   > rotations, with z = M when SIDE = 'L' and z = N when SIDE = 'R',   
   > and P**T is the transpose of P.   
   >   
   > When DIRECT = 'F' (Forward sequence), then   
   >   
   >    P = P(z-1) * ... * P(2) * P(1)   
   >   
   > and when DIRECT = 'B' (Backward sequence), then   
   >   
   >    P = P(1) * P(2) * ... * P(z-1)   
   >   
   > where P(k) is a plane rotation matrix defined by the 2-by-2 rotation   
   >   
   >    R(k) = (  c(k)  s(k) )   
   >         = ( -s(k)  c(k) ).   
   >   
   > When PIVOT = 'V' (Variable pivot), the rotation is performed   
   > for the plane (k,k+1), i.e., P(k) has the form   
   >   
   >    P(k) = (  1                                            )   
   >           (       ...                                     )   
   >           (              1                                )   
   >           (                   c(k)  s(k)                  )   
   >           (                  -s(k)  c(k)                  )   
   >           (                                1              )   
   >           (                                     ...       )   
   >           (                                            1  )   
   >   
   > where R(k) appears as a rank-2 modification to the identity matrix in   
   > rows and columns k and k+1.   
   >   
   > When PIVOT = 'T' (Top pivot), the rotation is performed for the   
   > plane (1,k+1), so P(k) has the form   
   >   
   >    P(k) = (  c(k)                    s(k)                 )   
   >           (         1                                     )   
   >           (              ...                              )   
   >           (                     1                         )   
   >           ( -s(k)                    c(k)                 )   
   >           (                                 1             )   
   >           (                                      ...      )   
   >           (                                             1 )   
   >   
   > where R(k) appears in rows and columns 1 and k+1.   
   >   
   > Similarly, when PIVOT = 'B' (Bottom pivot), the rotation is   
   > performed for the plane (k,z), giving P(k) the form   
   >   
   >    P(k) = ( 1                                             )   
   >           (      ...                                      )   
   >           (             1                                 )   
   >           (                  c(k)                    s(k) )   
   >           (                         1                     )   
   >           (                              ...              )   
   >           (                                     1         )   
   >           (                 -s(k)                    c(k) )   
   >   
   > where R(k) appears in rows and columns k and z.  The rotations are   
   > performed without ever forming P(k) explicitly.   
   > \endverbatim   

    Arguments:   
    ==========   

   > \param[in] SIDE   
   > \verbatim   
   >          SIDE is CHARACTER*1   
   >          Specifies whether the plane rotation matrix P is applied to   
   >          A on the left or the right.   
   >          = 'L':  Left, compute A := P*A   
   >          = 'R':  Right, compute A:= A*P**T   
   > \endverbatim   
   >   
   > \param[in] PIVOT   
   > \verbatim   
   >          PIVOT is CHARACTER*1   
   >          Specifies the plane for which P(k) is a plane rotation   
   >          matrix.   
   >          = 'V':  Variable pivot, the plane (k,k+1)   
   >          = 'T':  Top pivot, the plane (1,k+1)   
   >          = 'B':  Bottom pivot, the plane (k,z)   
   > \endverbatim   
   >   
   > \param[in] DIRECT   
   > \verbatim   
   >          DIRECT is CHARACTER*1   
   >          Specifies whether P is a forward or backward sequence of   
   >          plane rotations.   
   >          = 'F':  Forward, P = P(z-1)*...*P(2)*P(1)   
   >          = 'B':  Backward, P = P(1)*P(2)*...*P(z-1)   
   > \endverbatim   
   >   
   > \param[in] M   
   > \verbatim   
   >          M is INTEGER   
   >          The number of rows of the matrix A.  If m <= 1, an immediate   
   >          return is effected.   
   > \endverbatim   
   >   
   > \param[in] N   
   > \verbatim   
   >          N is INTEGER   
   >          The number of columns of the matrix A.  If n <= 1, an   
   >          immediate return is effected.   
   > \endverbatim   
   >   
   > \param[in] C   
   > \verbatim   
   >          C is DOUBLE PRECISION array, dimension   
   >                  (M-1) if SIDE = 'L'   
   >                  (N-1) if SIDE = 'R'   
   >          The cosines c(k) of the plane rotations.   
   > \endverbatim   
   >   
   > \param[in] S   
   > \verbatim   
   >          S is DOUBLE PRECISION array, dimension   
   >                  (M-1) if SIDE = 'L'   
   >                  (N-1) if SIDE = 'R'   
   >          The sines s(k) of the plane rotations.  The 2-by-2 plane   
   >          rotation part of the matrix P(k), R(k), has the form   
   >          R(k) = (  c(k)  s(k) )   
   >                 ( -s(k)  c(k) ).   
   > \endverbatim   
   >   
   > \param[in,out] A   
   > \verbatim   
   >          A is DOUBLE PRECISION array, dimension (LDA,N)   
   >          The M-by-N matrix A.  On exit, A is overwritten by P*A if   
   >          SIDE = 'R' or by A*P**T if SIDE = 'L'.   
   > \endverbatim   
   >   
   > \param[in] LDA   
   > \verbatim   
   >          LDA is INTEGER   
   >          The leading dimension of the array A.  LDA >= max(1,M).   
   > \endverbatim   

    Authors:   
    ========   

   > \author Univ. of Tennessee   
   > \author Univ. of California Berkeley   
   > \author Univ. of Colorado Denver   
   > \author NAG Ltd.   

   > \date September 2012   

   > \ingroup auxOTHERauxiliary   

    =====================================================================   
   Subroutine */ int igraphdlasr_(char *side, char *pivot, char *direct, integer *m,
	 integer *n, doublereal *c__, doublereal *s, doublereal *a, integer *
	lda)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2;

    /* Local variables */
    integer i__, j, info;
    doublereal temp;
    extern logical igraphlsame_(char *, char *);
    doublereal ctemp, stemp;
    extern /* Subroutine */ int igraphxerbla_(char *, integer *, ftnlen);


/*  -- LAPACK auxiliary routine (version 3.4.2) --   
    -- LAPACK is a software package provided by Univ. of Tennessee,    --   
    -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--   
       September 2012   


    =====================================================================   


       Test the input parameters   

       Parameter adjustments */
    --c__;
    --s;
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;

    /* Function Body */
    info = 0;
    if (! (igraphlsame_(side, "L") || igraphlsame_(side, "R"))) {
	info = 1;
    } else if (! (igraphlsame_(pivot, "V") || igraphlsame_(pivot, 
	    "T") || igraphlsame_(pivot, "B"))) {
	info = 2;
    } else if (! (igraphlsame_(direct, "F") || igraphlsame_(direct, 
	    "B"))) {
	info = 3;
    } else if (*m < 0) {
	info = 4;
    } else if (*n < 0) {
	info = 5;
    } else if (*lda < max(1,*m)) {
	info = 9;
    }
    if (info != 0) {
	igraphxerbla_("DLASR ", &info, (ftnlen)6);
	return 0;
    }

/*     Quick return if possible */

    if (*m == 0 || *n == 0) {
	return 0;
    }
    if (igraphlsame_(side, "L")) {

/*        Form  P * A */

	if (igraphlsame_(pivot, "V")) {
	    if (igraphlsame_(direct, "F")) {
		i__1 = *m - 1;
		for (j = 1; j <= i__1; ++j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__2 = *n;
			for (i__ = 1; i__ <= i__2; ++i__) {
			    temp = a[j + 1 + i__ * a_dim1];
			    a[j + 1 + i__ * a_dim1] = ctemp * temp - stemp * 
				    a[j + i__ * a_dim1];
			    a[j + i__ * a_dim1] = stemp * temp + ctemp * a[j 
				    + i__ * a_dim1];
/* L10: */
			}
		    }
/* L20: */
		}
	    } else if (igraphlsame_(direct, "B")) {
		for (j = *m - 1; j >= 1; --j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__1 = *n;
			for (i__ = 1; i__ <= i__1; ++i__) {
			    temp = a[j + 1 + i__ * a_dim1];
			    a[j + 1 + i__ * a_dim1] = ctemp * temp - stemp * 
				    a[j + i__ * a_dim1];
			    a[j + i__ * a_dim1] = stemp * temp + ctemp * a[j 
				    + i__ * a_dim1];
/* L30: */
			}
		    }
/* L40: */
		}
	    }
	} else if (igraphlsame_(pivot, "T")) {
	    if (igraphlsame_(direct, "F")) {
		i__1 = *m;
		for (j = 2; j <= i__1; ++j) {
		    ctemp = c__[j - 1];
		    stemp = s[j - 1];
		    if (ctemp != 1. || stemp != 0.) {
			i__2 = *n;
			for (i__ = 1; i__ <= i__2; ++i__) {
			    temp = a[j + i__ * a_dim1];
			    a[j + i__ * a_dim1] = ctemp * temp - stemp * a[
				    i__ * a_dim1 + 1];
			    a[i__ * a_dim1 + 1] = stemp * temp + ctemp * a[
				    i__ * a_dim1 + 1];
/* L50: */
			}
		    }
/* L60: */
		}
	    } else if (igraphlsame_(direct, "B")) {
		for (j = *m; j >= 2; --j) {
		    ctemp = c__[j - 1];
		    stemp = s[j - 1];
		    if (ctemp != 1. || stemp != 0.) {
			i__1 = *n;
			for (i__ = 1; i__ <= i__1; ++i__) {
			    temp = a[j + i__ * a_dim1];
			    a[j + i__ * a_dim1] = ctemp * temp - stemp * a[
				    i__ * a_dim1 + 1];
			    a[i__ * a_dim1 + 1] = stemp * temp + ctemp * a[
				    i__ * a_dim1 + 1];
/* L70: */
			}
		    }
/* L80: */
		}
	    }
	} else if (igraphlsame_(pivot, "B")) {
	    if (igraphlsame_(direct, "F")) {
		i__1 = *m - 1;
		for (j = 1; j <= i__1; ++j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__2 = *n;
			for (i__ = 1; i__ <= i__2; ++i__) {
			    temp = a[j + i__ * a_dim1];
			    a[j + i__ * a_dim1] = stemp * a[*m + i__ * a_dim1]
				     + ctemp * temp;
			    a[*m + i__ * a_dim1] = ctemp * a[*m + i__ * 
				    a_dim1] - stemp * temp;
/* L90: */
			}
		    }
/* L100: */
		}
	    } else if (igraphlsame_(direct, "B")) {
		for (j = *m - 1; j >= 1; --j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__1 = *n;
			for (i__ = 1; i__ <= i__1; ++i__) {
			    temp = a[j + i__ * a_dim1];
			    a[j + i__ * a_dim1] = stemp * a[*m + i__ * a_dim1]
				     + ctemp * temp;
			    a[*m + i__ * a_dim1] = ctemp * a[*m + i__ * 
				    a_dim1] - stemp * temp;
/* L110: */
			}
		    }
/* L120: */
		}
	    }
	}
    } else if (igraphlsame_(side, "R")) {

/*        Form A * P**T */

	if (igraphlsame_(pivot, "V")) {
	    if (igraphlsame_(direct, "F")) {
		i__1 = *n - 1;
		for (j = 1; j <= i__1; ++j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__2 = *m;
			for (i__ = 1; i__ <= i__2; ++i__) {
			    temp = a[i__ + (j + 1) * a_dim1];
			    a[i__ + (j + 1) * a_dim1] = ctemp * temp - stemp *
				     a[i__ + j * a_dim1];
			    a[i__ + j * a_dim1] = stemp * temp + ctemp * a[
				    i__ + j * a_dim1];
/* L130: */
			}
		    }
/* L140: */
		}
	    } else if (igraphlsame_(direct, "B")) {
		for (j = *n - 1; j >= 1; --j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__1 = *m;
			for (i__ = 1; i__ <= i__1; ++i__) {
			    temp = a[i__ + (j + 1) * a_dim1];
			    a[i__ + (j + 1) * a_dim1] = ctemp * temp - stemp *
				     a[i__ + j * a_dim1];
			    a[i__ + j * a_dim1] = stemp * temp + ctemp * a[
				    i__ + j * a_dim1];
/* L150: */
			}
		    }
/* L160: */
		}
	    }
	} else if (igraphlsame_(pivot, "T")) {
	    if (igraphlsame_(direct, "F")) {
		i__1 = *n;
		for (j = 2; j <= i__1; ++j) {
		    ctemp = c__[j - 1];
		    stemp = s[j - 1];
		    if (ctemp != 1. || stemp != 0.) {
			i__2 = *m;
			for (i__ = 1; i__ <= i__2; ++i__) {
			    temp = a[i__ + j * a_dim1];
			    a[i__ + j * a_dim1] = ctemp * temp - stemp * a[
				    i__ + a_dim1];
			    a[i__ + a_dim1] = stemp * temp + ctemp * a[i__ + 
				    a_dim1];
/* L170: */
			}
		    }
/* L180: */
		}
	    } else if (igraphlsame_(direct, "B")) {
		for (j = *n; j >= 2; --j) {
		    ctemp = c__[j - 1];
		    stemp = s[j - 1];
		    if (ctemp != 1. || stemp != 0.) {
			i__1 = *m;
			for (i__ = 1; i__ <= i__1; ++i__) {
			    temp = a[i__ + j * a_dim1];
			    a[i__ + j * a_dim1] = ctemp * temp - stemp * a[
				    i__ + a_dim1];
			    a[i__ + a_dim1] = stemp * temp + ctemp * a[i__ + 
				    a_dim1];
/* L190: */
			}
		    }
/* L200: */
		}
	    }
	} else if (igraphlsame_(pivot, "B")) {
	    if (igraphlsame_(direct, "F")) {
		i__1 = *n - 1;
		for (j = 1; j <= i__1; ++j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__2 = *m;
			for (i__ = 1; i__ <= i__2; ++i__) {
			    temp = a[i__ + j * a_dim1];
			    a[i__ + j * a_dim1] = stemp * a[i__ + *n * a_dim1]
				     + ctemp * temp;
			    a[i__ + *n * a_dim1] = ctemp * a[i__ + *n * 
				    a_dim1] - stemp * temp;
/* L210: */
			}
		    }
/* L220: */
		}
	    } else if (igraphlsame_(direct, "B")) {
		for (j = *n - 1; j >= 1; --j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__1 = *m;
			for (i__ = 1; i__ <= i__1; ++i__) {
			    temp = a[i__ + j * a_dim1];
			    a[i__ + j * a_dim1] = stemp * a[i__ + *n * a_dim1]
				     + ctemp * temp;
			    a[i__ + *n * a_dim1] = ctemp * a[i__ + *n * 
				    a_dim1] - stemp * temp;
/* L230: */
			}
		    }
/* L240: */
		}
	    }
	}
    }

    return 0;

/*     End of DLASR */

} /* igraphdlasr_ */

