Procedure

   void mxmg_c ( const void    * m1,
                 const void    * m2,
                 SpiceInt        nrow1,
                 SpiceInt        ncol1,
                 SpiceInt        ncol2,
                 void          * mout   )

Abstract

   Multiply two double precision matrices of arbitrary size.

Required_Reading

   None.

Keywords

   MATRIX

Brief_I/O

   VARIABLE  I/O  DESCRIPTION
   --------  ---  --------------------------------------------------
   m1         I   nrow1 X ncol1 double precision matrix.
   m2         I   ncol1 X ncol2 double precision matrix.
   nrow1      I   Row dimension of m1 (and also mout).
   ncol1      I   Column dimension of m1 and row dimension of m2.
   ncol2      I   Column dimension of m2 (and also mout).
   mout       O   nrow1 X ncol2 double precision matrix.

Detailed_Input

   m1         is any double precision matrix of arbitrary size.

   m2         is any double precision matrix of arbitrary size.
              The number of rows in m2 must match the number of
              columns in m1.

   nrow1      is the number of rows in both m1 and mout.

   ncol1      is the number of columns in m1 and (by necessity)
              the number of rows of m2.

   ncol2      is the number of columns in both m2 and mout.

Detailed_Output

   mout
              mout is the product matrix defined by

                 mout = (m1) x (m2)

              mout is a double precision matrix of dimension nrow1 x
              ncol2.

              mout may overwrite m1 or m2.  Note that this capability
              does not exist in the Fortran version of SPICELIB; in the
              Fortran version, the output must not overwrite either
              input.

Parameters

   None.

Exceptions

   1) If dynamic allocation of memory fails, the error
      SPICE(MEMALLOCFAILED) is signalled.

Files

   None.

Particulars

   The code reflects precisely the following mathematical expression

   For each value of the subscript i from 1 to nrow1, and j from 1
   to ncol2:

      mout(i,j) = Summation from k=1 to ncol1 of  m1(i,k) * m2(k,j)

Examples

   Let

      m1 = | 1.0  4.0 |    and  m2 =  | 1.0  3.0  5.0 |
           |          |                               |
           | 2.0  5.0 |               | 2.0  4.0  6.0 |
           |          |
           | 3.0  6.0 |

   and

      nrow1  = 3
      ncol1  = 2
      ncol2  = 3

   Then the call


      mxmg ( m1, m2, nrow1, ncol1, ncol2, mout );


   produces the matrix

      mout = |  9.0  19.0  29.0 |
             |                  |
             | 12.0  26.0  40.0 |
             |                  |
             | 15.0  33.0  51.0 |

Restrictions

   1) No error checking is performed to prevent numeric overflow or
      underflow.

   2) No error checking performed to determine if the input and
      output matrices have, in fact, been correctly dimensioned.

Literature_References

   None.

Author_and_Institution

   N.J. Bachman       (JPL)
   W.M. Owen          (JPL)

Version

   -CSPICE Version 1.1.2, 16-JAN-2008   (EDW)

      Corrected typos in header titles:
      
      Detailed Input to Detailed_Input
      Detailed Output to Detailed_Output
      
   -CSPICE Version 1.1.1, 10-NOV-2006   (EDW)

      Added Parameters section header. 

   -CSPICE Version 1.1.0, 28-AUG-2001 (NJB)

      Const-qualified input arrays.

   -CSPICE Version 1.0.0, 16-APR-1999 (NJB)

Index_Entries

   matrix times matrix n-dimensional_case

Link to routine mxmg_c source file mxmg_c.c