LCOV - code coverage report
Current view: top level - libavutil - lls.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 49 50 98.0 %
Date: 2017-12-15 02:19:58 Functions: 4 4 100.0 %

          Line data    Source code
       1             : /*
       2             :  * linear least squares model
       3             :  *
       4             :  * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
       5             :  *
       6             :  * This file is part of FFmpeg.
       7             :  *
       8             :  * FFmpeg is free software; you can redistribute it and/or
       9             :  * modify it under the terms of the GNU Lesser General Public
      10             :  * License as published by the Free Software Foundation; either
      11             :  * version 2.1 of the License, or (at your option) any later version.
      12             :  *
      13             :  * FFmpeg is distributed in the hope that it will be useful,
      14             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      15             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      16             :  * Lesser General Public License for more details.
      17             :  *
      18             :  * You should have received a copy of the GNU Lesser General Public
      19             :  * License along with FFmpeg; if not, write to the Free Software
      20             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      21             :  */
      22             : 
      23             : /**
      24             :  * @file
      25             :  * linear least squares model
      26             :  */
      27             : 
      28             : #include <math.h>
      29             : #include <string.h>
      30             : 
      31             : #include "attributes.h"
      32             : #include "internal.h"
      33             : #include "version.h"
      34             : #include "lls.h"
      35             : 
      36      836444 : static void update_lls(LLSModel *m, const double *var)
      37             : {
      38             :     int i, j;
      39             : 
      40     8364440 :     for (i = 0; i <= m->indep_count; i++) {
      41    45167976 :         for (j = i; j <= m->indep_count; j++) {
      42    37639980 :             m->covariance[i][j] += var[i] * var[j];
      43             :         }
      44             :     }
      45      836444 : }
      46             : 
      47         182 : void avpriv_solve_lls(LLSModel *m, double threshold, unsigned short min_order)
      48             : {
      49             :     int i, j, k;
      50         182 :     double (*factor)[MAX_VARS_ALIGN] = (void *) &m->covariance[1][0];
      51         182 :     double (*covar) [MAX_VARS_ALIGN] = (void *) &m->covariance[1][1];
      52         182 :     double *covar_y                = m->covariance[0];
      53         182 :     int count                      = m->indep_count;
      54             : 
      55        1638 :     for (i = 0; i < count; i++) {
      56        8008 :         for (j = i; j < count; j++) {
      57        6552 :             double sum = covar[i][j];
      58             : 
      59       21840 :             for (k = 0; k <= i-1; k++)
      60       15288 :                 sum -= factor[i][k] * factor[j][k];
      61             : 
      62        6552 :             if (i == j) {
      63        1456 :                 if (sum < threshold)
      64           0 :                     sum = 1.0;
      65        1456 :                 factor[i][i] = sqrt(sum);
      66             :             } else {
      67        5096 :                 factor[j][i] = sum / factor[i][i];
      68             :             }
      69             :         }
      70             :     }
      71             : 
      72        1638 :     for (i = 0; i < count; i++) {
      73        1456 :         double sum = covar_y[i + 1];
      74             : 
      75        6552 :         for (k = 0; k <= i-1; k++)
      76        5096 :             sum -= factor[i][k] * m->coeff[0][k];
      77             : 
      78        1456 :         m->coeff[0][i] = sum / factor[i][i];
      79             :     }
      80             : 
      81        1638 :     for (j = count - 1; j >= min_order; j--) {
      82        8008 :         for (i = j; i >= 0; i--) {
      83        6552 :             double sum = m->coeff[0][i];
      84             : 
      85       21840 :             for (k = i + 1; k <= j; k++)
      86       15288 :                 sum -= factor[k][i] * m->coeff[j][k];
      87             : 
      88        6552 :             m->coeff[j][i] = sum / factor[i][i];
      89             :         }
      90             : 
      91        1456 :         m->variance[j] = covar_y[0];
      92             : 
      93        8008 :         for (i = 0; i <= j; i++) {
      94        6552 :             double sum = m->coeff[j][i] * covar[i][i] - 2 * covar_y[i + 1];
      95             : 
      96       21840 :             for (k = 0; k < i; k++)
      97       15288 :                 sum += 2 * m->coeff[j][k] * covar[k][i];
      98             : 
      99        6552 :             m->variance[j] += m->coeff[j][i] * sum;
     100             :         }
     101             :     }
     102         182 : }
     103             : 
     104      836444 : static double evaluate_lls(LLSModel *m, const double *param, int order)
     105             : {
     106             :     int i;
     107      836444 :     double out = 0;
     108             : 
     109     7527996 :     for (i = 0; i <= order; i++)
     110     6691552 :         out += param[i] * m->coeff[order][i];
     111             : 
     112      836444 :     return out;
     113             : }
     114             : 
     115         182 : av_cold void avpriv_init_lls(LLSModel *m, int indep_count)
     116             : {
     117         182 :     memset(m, 0, sizeof(LLSModel));
     118         182 :     m->indep_count = indep_count;
     119         182 :     m->update_lls = update_lls;
     120         182 :     m->evaluate_lls = evaluate_lls;
     121             :     if (ARCH_X86)
     122         182 :         ff_init_lls_x86(m);
     123         182 : }

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