| /* @(#) Calculates the mean and the standard deviation (std) of |
| * @(#) an int or double buffer of size size. |
| * @(#) |
| * @(#) Usage: |
| * @(#) int im__mean_std_double_buffer(buffer, size, pmean, pstd) |
| * @(#) double *buffer; |
| * @(#) int size; |
| * @(#) double *pmean, *pstd; |
| * @(#) |
| * @(#) int im__mean_std_int_buffer(buffer, size, pmean, pstd) |
| * @(#) int *buffer; |
| * @(#) int size; |
| * @(#) double *pmean, *pstd; |
| * @(#) |
| * @(#) Both functions return 0 on success and -1 on error |
| * |
| * Copyright: N. Dessipris 1991 |
| * Written on: 2/12/1991 |
| * Updated on: 2/12/1991 |
| * 22/7/93 JC |
| * - externs removed |
| */ |
| |
| /* |
| |
| 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 <stdlib.h> |
| #include <math.h> |
| |
| #include <vips/vips.h> |
| |
| #ifdef WITH_DMALLOC |
| #include <dmalloc.h> |
| #endif /*WITH_DMALLOC*/ |
| |
| int |
| im__mean_std_double_buffer( double *buffer, int size, |
| double *pmean, double *pstd ) |
| { |
| double mean, std; |
| register int i; |
| double sumf; |
| double temp; |
| double *pbuffer; |
| double sumf2; |
| double correction; /* calulates the correction term for the variance */ |
| double variance; /* = (sumf2 - correction)/n */ |
| |
| if (size <= 0) { |
| im_error( "im_mean_std_double_buffer", "%s", _( "wrong args") ); |
| return(-1); |
| } |
| mean = 0.0; std = 0.0; |
| sumf = 0.0; sumf2 = 0.0; |
| pbuffer = buffer; |
| for (i=0; i<size; i++) { |
| temp = *pbuffer++; |
| sumf += temp; |
| sumf2 += (temp*temp); |
| } |
| |
| correction = (sumf * sumf)/((double)size); |
| mean = sumf/((double)size); |
| variance = ( sumf2 - correction)/((double)size); |
| std = sqrt(variance); |
| *pmean = mean; |
| *pstd = std; |
| |
| return( 0 ); |
| } |
| |
| int |
| im__mean_std_int_buffer( int *buffer, int size, |
| double *pmean, double *pstd ) |
| { |
| double mean, std; |
| register int i; |
| int sumf; |
| int temp; |
| int *pbuffer; |
| int sumf2; |
| double correction; /* calulates the correction term for the variance */ |
| double variance; /* = (sumf2 - correction)/n */ |
| |
| if (size <= 0) { |
| im_error( "im_mean_std_int_buffer", "%s", _( "wrong args") ); |
| return(-1); |
| } |
| |
| mean = 0.0; std = 0.0; |
| sumf = 0; sumf2 = 0; |
| pbuffer = buffer; |
| for (i=0; i<size; i++) { |
| temp = *pbuffer++; |
| sumf += temp; |
| sumf2 += (temp*temp); |
| } |
| |
| correction = ((double)(sumf * sumf))/((double)size); |
| mean = ((double)sumf)/((double)size); |
| variance = ( sumf2 - correction)/((double)size); |
| std = sqrt(variance); |
| *pmean = mean; |
| *pstd = std; |
| |
| return(0); |
| } |