text: /* xpsgip.f -- translated by f2c (version 19980913).
     You must link the resulting object file with the libraries:
  	-lf2c -lm   (in that order)
  */
  
  #include "f2c.h"
  
  /* $Procedure XPSGIP ( Transpose a matrix, general dimension, in place ) */
  /* Subroutine */ int xpsgip_(integer *nrow, integer *ncol, doublereal *matrix)
  {
      integer dest;
      doublereal temp;
      integer k, m, n, r__, moved, start;
      doublereal source;
      integer nmoves;
  
  /* $ Abstract */
  
  /*     Transpose a matrix of arbitrary size and shape in place. */
  
  /* $ Disclaimer */
  
  /*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
  /*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
  /*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
  /*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
  /*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
  /*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
  /*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
  /*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
  /*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
  /*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */
  
  /*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
  /*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
  /*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
  /*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
  /*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
  /*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */
  
  /*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
  /*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
  /*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
  /*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */
  
  /* $ Required_Reading */
  
  /*     None. */
  
  /* $ Keywords */
  
  /*     MATRIX */
  
  /* $ Declarations */
  /* $ Brief_I/O */
  
  /*     VARIABLE  I/O  DESCRIPTION */
  /*     --------  ---  -------------------------------------------------- */
  /*     NROW       I   Number of rows of input matrix. */
  /*     NCOL       I   Number of columns of input matrix. */
  /*     MATRIX    I-O  Matrix to be transposed/transposed matrix. */
  
  /* $ Detailed_Input */
  
  /*     MATRIX     Matrix to be transposed. */
  
  /*     NROW       Number of rows of input matrix MATRIX. */
  
  /*     NCOL       Number of columns of input matrix MATRIX. */
  
  /* $ Detailed_Output */
  
  /*     MATRIX     Transposed matrix:  element (i,j) of the input */
  /*                matrix is element (j,i) of the output matrix. */
  
  /* $ Parameters */
  
  /*     None. */
  
  /* $ Exceptions */
  
  /*     Error Free. */
  
  /*     1) If either NROW or NCOL is less than or equal to zero, no action */
  /*        is taken. The routine simply returns. */
  
  /* $ Files */
  
  /*     None. */
  
  /* $ Particulars */
  
  /*     This routine replaces the input matrix MATRIX with its transpose. */
  
  /*     NOTE:  The matrix MATRIX is declared one-dimensional for */
  /*            computational purposes only.  The calling program may */
  /*            declare it as MATRIX(NROW,NCOL) or MATRIX(NCOL,NROW). */
  
  /*            This routine assumes that the elements of the matrix to be */
  /*            transformed are stored in contiguous memory locations as */
  /*            shown here.  On output these elements will be rearranged */
  /*            in consecutive memory locations as shown. */
  
  /*               MATRIX on input      MATRIX on output */
  
  /*                m_11                m_11 */
  /*                m_21                m_12 */
  /*                m_31                m_13 */
  /*                 .                   . */
  /*                 .                   . */
  /*                 .                  m_1ncol */
  /*                m_nrow1             m_21 */
  /*                m_12                m_22 */
  /*                m_22                m_23 */
  /*                m_32                 . */
  /*                 .                   . */
  /*                 .                  m_2ncol */
  /*                 .                   . */
  /*                m_nrow2 */
  /*                 .                   . */
  
  /*                 .                   . */
  
  /*                 .                   . */
  /*                m_1ncol */
  /*                m_2ncol             m_nrow1 */
  /*                m_3ncol             m_nrow2 */
  /*                 .                  m_nrow3 */
  /*                 .                   . */
  /*                 .                   . */
  /*                m_nrowncol          m_nrowncol */
  
  
  /*     For those familiar with permutations, this algorithm relies */
  /*     upon the fact that the transposition of a matrix, which has */
  /*     been stored as a 1-dimensional array, is simply the action of a */
  /*     permutation applied to that array.  Since any permutation */
  /*     can be decomposed as a product of disjoint cycles, it is */
  /*     possible to transpose the matrix with only one additional */
  /*     storage register.  However, once a cycle has been computed */
  /*     it is necessary to find the next entry in the array that */
  /*     has not been moved by the permutation.  For this reason the */
  /*     algorithm is slower than would be necessary if the numbers */
  /*     of rows and columns were known in advance. */
  
  /* $ Examples */
  
  /*     This routine is provided for situation where it is convenient to */
  /*     transpose a general two-dimensional matrix */
  /*     in place rather than store the result in a */
  /*     separate array.  Note that the call */
  
  /*        CALL XPOSEG ( MATRIX, NROW, NCOL, MATRIX ) */
  
  /*     is not permitted by the ANSI Fortran 77 standard; this routine */
  /*     can be called instead to achieve the same result. */
  
  /* $ Restrictions */
  
  /*     None. */
  
  /* $ Author_and_Institution */
  
  /*     N.J. Bachman    (JPL) */
  /*     W.L. Taber      (JPL) */
  
  /* $ Literature_References */
  
  /*     None. */
  
  /* $ Version */
  
  /* -    SPICELIB Version 1.0.1, 19-SEP-2006 (EDW) */
  
  /*        Initial version date unknown. Version data entry */
  /*        added this date. */
  
  
  /* -& */
  /* $ Index_Entries */
  
  /*     transpose a matrix general */
  
  /* -& */
  
  /*     Local Variables */
  
  
  /*     Take care of dumb cases first. */
  
      if (*nrow <= 0 || *ncol <= 0) {
  	return 0;
      }
  
  /*     Use the abbreviations N and M for NROW and NCOL. */
  
      n = *nrow;
      m = *ncol;
  
  /*     Set up the upper bound for the number of objects to be moved and */
  /*     initialize the counters. */
  
      nmoves = n * m - 2;
      moved = 0;
      start = 1;
  
  /*     Until MOVED is equal to NMOVES, there is some matrix element that */
  /*     has not been moved to its proper location in the transpose matrix. */
  
      while(moved < nmoves) {
  	source = matrix[start];
  	k = start / n;
  	r__ = start - n * k;
  	dest = r__ * m + k;
  
  /*        Perform this cycle of the permutation.  We will be done when */
  /*        the destination of the next element is equal to the starting */
  /*        position of the first element to be moved in this cycle. */
  
  	while(dest != start) {
  	    temp = matrix[dest];
  	    matrix[dest] = source;
  	    source = temp;
  	    ++moved;
  	    k = dest / n;
  	    r__ = dest - k * n;
  	    dest = m * r__ + k;
  	}
  	matrix[dest] = source;
  	dest = 0;
  	++moved;
  
  /*        Find the next element of the matrix that has not already been */
  /*        moved by the transposition operation. */
  
  	if (moved < nmoves) {
  	    while(dest != start) {
  		++start;
  		k = start / n;
  		r__ = start - k * n;
  		dest = r__ * m + k;
  		while(dest > start) {
  		    k = dest / n;
  		    r__ = dest - k * n;
  		    dest = m * r__ + k;
  		}
  	    }
  	}
      }
      return 0;
  } /* xpsgip_ */
  
  