1 files changed, 102 insertions, 0 deletions
diff --git a/libavutil/tests/pca.c b/libavutil/tests/pca.c
new file mode 100644
index 0000000000..2d9eb8f56a
--- /dev/null
+++ b/libavutil/tests/pca.c
@@ -0,0 +1,102 @@
+/*
+ * 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;
+}