mtxmg_c |

## Procedurevoid mtxmg_c ( const void * m1, const void * m2, SpiceInt ncol1, SpiceInt nr1r2, SpiceInt ncol2, void * mout ) ## AbstractMultiply the transpose of a matrix with another matrix, both of arbitrary size. (The dimensions of the matrices must be compatible with this multiplication.) ## Required_ReadingNone. ## KeywordsMATRIX ## Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- m1 I nr1r2 X ncol1 double precision matrix. m2 I nr1r2 X ncol2 double precision matrix. ncol1 I Column dimension of m1 and row dimension of mout. nr1r2 I Row dimension of m1 and m2. ncol2 I Column dimension of m2 (and also mout). mout O Transpose of m1 times m2. ## Detailed_Inputm1 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 rows in m1. ncol1 is the number of columns in m1 and the number of rows of mout. nr1r2 is the number of rows in both m1 and (by necessity) m2. ncol2 is the number of columns in both m2 and mout. ## Detailed_Outputmout mout is the product matrix defined as the transpose of m1 times m2, that is t mout = (m1) x (m2) where the superscript t denotes the transpose of m1. mout is a double precision matrix of dimension ncol1 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. ## ParametersNone. ## Exceptions1) If dynamic allocation of memory fails, the error SPICE(MEMALLOCFAILED) is signalled. ## FilesNone. ## ParticularsThe code reflects precisely the following mathematical expression For each value of the subscript i from 1 to ncol1, and j from 1 to ncol2: mout(i,j) = Summation from k=1 to nr1r2 of m1(k,i) * m2(k,j) ## Examples1) Suppose that m1 = | 1 2 3 0 | | 1 1 1 1 | and that m2 = | 1 2 3 | | 0 0 0 | Then calling ## Restrictions1) 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_ReferencesNone. ## Author_and_InstitutionN.J. Bachman (JPL) W.M. Owen (JPL) ## Version-CSPICE Version 1.2.2, 16-JAN-2008 (EDW) Corrected typos in header titles: Detailed Input to Detailed_Input Detailed Output to Detailed_Output -CSPICE Version 1.2.1, 10-NOV-2006 (EDW) Added Parameters section header. -CSPICE Version 1.2.0, 28-AUG-2001 (NJB) Const-qualified input arrays. -CSPICE Version 1.0.0, 16-APR-1999 (NJB) ## Index_Entriesmatrix transpose times matrix n-dimensional_case |

Wed Apr 5 17:54:39 2017