| /* @(#) Multiplies two DOUBLEMASKs. Result matrix is made and returned. |
| * @(#) Pass the filename to set for the output. |
| * @(#) |
| * @(#) DOUBLEMASK * |
| * @(#) im_matmul( in1, in2, name ) |
| * @(#) DOUBLEMASK *in1, *in2; |
| * @(#) char *name; |
| * @(#) |
| * @(#) NULL for error. |
| * |
| * Copyright: 1990, K. Martinez and J. Cupitt |
| * |
| */ |
| |
| /* |
| |
| This file is part of VIPS. |
| |
| VIPS is free software; you can redistribute it and/or modify |
| it under the terms of the GNU Lesser General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| |
| */ |
| |
| /* |
| |
| These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk |
| |
| */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include <config.h> |
| #endif /*HAVE_CONFIG_H*/ |
| #include <vips/intl.h> |
| |
| #include <stdio.h> |
| |
| #include <vips/vips.h> |
| |
| #ifdef WITH_DMALLOC |
| #include <dmalloc.h> |
| #endif /*WITH_DMALLOC*/ |
| |
| /* MATRIX MULTIPLY? |
| */ |
| DOUBLEMASK * |
| im_matmul( DOUBLEMASK *in1, DOUBLEMASK *in2, const char *name ) |
| { |
| int xc, yc, col; |
| double sum; |
| DOUBLEMASK *mat; |
| double *out, *a, *b; |
| double *s1, *s2; |
| |
| /* Check matrix sizes. |
| */ |
| if( in1->xsize != in2->ysize ) { |
| im_error( "im_matmul", "%s", _( "bad sizes" ) ); |
| return( NULL ); |
| } |
| |
| /* Allocate output matrix. |
| */ |
| if( !(mat = im_create_dmask( name, in2->xsize, in1->ysize )) ) { |
| im_error( "im_matmul", "%s", _( "unable to allocate output mask" ) ); |
| return( NULL ); |
| } |
| |
| /* Multiply. |
| */ |
| out = mat->coeff; |
| s1 = in1->coeff; |
| |
| for( yc = 0; yc < in1->ysize; yc++ ) { |
| s2 = in2->coeff; |
| |
| for( col = 0; col < in2->xsize; col++ ) { |
| /* Get ready to sweep a row. |
| */ |
| sum = 0.0; |
| a = s1; |
| b = s2; |
| |
| for( sum = 0.0, xc = 0; xc < in1->xsize; xc++ ) { |
| sum += *a++ * *b; |
| b += in2->xsize; |
| } |
| |
| *out++ = sum; |
| s2++; |
| } |
| |
| s1 += in1->xsize; |
| } |
| |
| return( mat ); |
| } |