* commit 'a6a750c7ef240b72ce01e9653343a0ddf247d196': tests: Move all test programs to a subdirectory Merged-by: Clément Bœsch <clement@stupeflix.com>
		
			
				
	
	
		
			103 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			103 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * principal component analysis (PCA)
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 * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include "libavutil/pca.c"
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#include "libavutil/lfg.h"
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#undef printf
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#include <stdio.h>
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#include <stdlib.h>
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int main(void){
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    PCA *pca;
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    int i, j, k;
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#define LEN 8
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    double eigenvector[LEN*LEN];
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    double eigenvalue[LEN];
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    AVLFG prng;
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    av_lfg_init(&prng, 1);
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    pca= ff_pca_init(LEN);
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    for(i=0; i<9000000; i++){
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        double v[2*LEN+100];
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        double sum=0;
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        int pos = av_lfg_get(&prng) % LEN;
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        int v2  = av_lfg_get(&prng) % 101 - 50;
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        v[0]    = av_lfg_get(&prng) % 101 - 50;
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        for(j=1; j<8; j++){
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            if(j<=pos) v[j]= v[0];
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            else       v[j]= v2;
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            sum += v[j];
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        }
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/*        for(j=0; j<LEN; j++){
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            v[j] -= v[pos];
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        }*/
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//        sum += av_lfg_get(&prng) % 10;
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/*        for(j=0; j<LEN; j++){
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            v[j] -= sum/LEN;
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        }*/
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//        lbt1(v+100,v+100,LEN);
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        ff_pca_add(pca, v);
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    }
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    ff_pca(pca, eigenvector, eigenvalue);
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    for(i=0; i<LEN; i++){
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        pca->count= 1;
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        pca->mean[i]= 0;
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//        (0.5^|x|)^2 = 0.5^2|x| = 0.25^|x|
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//        pca.covariance[i + i*LEN]= pow(0.5, fabs
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        for(j=i; j<LEN; j++){
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            printf("%f ", pca->covariance[i + j*LEN]);
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        }
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        printf("\n");
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    }
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    for(i=0; i<LEN; i++){
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        double v[LEN];
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        double error=0;
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        memset(v, 0, sizeof(v));
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        for(j=0; j<LEN; j++){
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            for(k=0; k<LEN; k++){
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                v[j] += pca->covariance[FFMIN(k,j) + FFMAX(k,j)*LEN] * eigenvector[i + k*LEN];
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            }
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            v[j] /= eigenvalue[i];
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            error += fabs(v[j] - eigenvector[i + j*LEN]);
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        }
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        printf("%f ", error);
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    }
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    printf("\n");
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    for(i=0; i<LEN; i++){
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        for(j=0; j<LEN; j++){
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            printf("%9.6f ", eigenvector[i + j*LEN]);
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        }
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        printf("  %9.1f %f\n", eigenvalue[i], eigenvalue[i]/eigenvalue[0]);
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    }
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    return 0;
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}
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