103 lines
2.7 KiB
C
Executable File
103 lines
2.7 KiB
C
Executable File
/*
|
|
* principal component analysis (PCA)
|
|
* Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg 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 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg 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 FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include "libavutil/pca.c"
|
|
#include "libavutil/lfg.h"
|
|
|
|
#undef printf
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
|
|
int main(void){
|
|
PCA *pca;
|
|
int i, j, k;
|
|
#define LEN 8
|
|
double eigenvector[LEN*LEN];
|
|
double eigenvalue[LEN];
|
|
AVLFG prng;
|
|
|
|
av_lfg_init(&prng, 1);
|
|
|
|
pca= ff_pca_init(LEN);
|
|
|
|
for(i=0; i<9000000; i++){
|
|
double v[2*LEN+100];
|
|
double sum=0;
|
|
int pos = av_lfg_get(&prng) % LEN;
|
|
int v2 = av_lfg_get(&prng) % 101 - 50;
|
|
v[0] = av_lfg_get(&prng) % 101 - 50;
|
|
for(j=1; j<8; j++){
|
|
if(j<=pos) v[j]= v[0];
|
|
else v[j]= v2;
|
|
sum += v[j];
|
|
}
|
|
/* for(j=0; j<LEN; j++){
|
|
v[j] -= v[pos];
|
|
}*/
|
|
// sum += av_lfg_get(&prng) % 10;
|
|
/* for(j=0; j<LEN; j++){
|
|
v[j] -= sum/LEN;
|
|
}*/
|
|
// lbt1(v+100,v+100,LEN);
|
|
ff_pca_add(pca, v);
|
|
}
|
|
|
|
|
|
ff_pca(pca, eigenvector, eigenvalue);
|
|
for(i=0; i<LEN; i++){
|
|
pca->count= 1;
|
|
pca->mean[i]= 0;
|
|
|
|
// (0.5^|x|)^2 = 0.5^2|x| = 0.25^|x|
|
|
|
|
|
|
// pca.covariance[i + i*LEN]= pow(0.5, fabs
|
|
for(j=i; j<LEN; j++){
|
|
printf("%f ", pca->covariance[i + j*LEN]);
|
|
}
|
|
printf("\n");
|
|
}
|
|
|
|
for(i=0; i<LEN; i++){
|
|
double v[LEN];
|
|
double error=0;
|
|
memset(v, 0, sizeof(v));
|
|
for(j=0; j<LEN; j++){
|
|
for(k=0; k<LEN; k++){
|
|
v[j] += pca->covariance[FFMIN(k,j) + FFMAX(k,j)*LEN] * eigenvector[i + k*LEN];
|
|
}
|
|
v[j] /= eigenvalue[i];
|
|
error += fabs(v[j] - eigenvector[i + j*LEN]);
|
|
}
|
|
printf("%f ", error);
|
|
}
|
|
printf("\n");
|
|
|
|
for(i=0; i<LEN; i++){
|
|
for(j=0; j<LEN; j++){
|
|
printf("%9.6f ", eigenvector[i + j*LEN]);
|
|
}
|
|
printf(" %9.1f %f\n", eigenvalue[i], eigenvalue[i]/eigenvalue[0]);
|
|
}
|
|
|
|
return 0;
|
|
}
|