class_days_pc_clusters.c

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00001 /* ***************************************************** */
00002 /* Classification subroutine: find the closest cluster   */
00003 /* of the principal components for each given day        */
00004 /* in EOF space.                                         */
00005 /* class_days_pc_clusters.c                             */
00006 /* ***************************************************** */
00007 /* Author: Christian Page, CERFACS, Toulouse, France.    */
00008 /* ***************************************************** */
00013 /* LICENSE BEGIN
00014 
00015 Copyright Cerfacs (Christian Page) (2015)
00016 
00017 christian.page@cerfacs.fr
00018 
00019 This software is a computer program whose purpose is to downscale climate
00020 scenarios using a statistical methodology based on weather regimes.
00021 
00022 This software is governed by the CeCILL license under French law and
00023 abiding by the rules of distribution of free software. You can use, 
00024 modify and/ or redistribute the software under the terms of the CeCILL
00025 license as circulated by CEA, CNRS and INRIA at the following URL
00026 "http://www.cecill.info". 
00027 
00028 As a counterpart to the access to the source code and rights to copy,
00029 modify and redistribute granted by the license, users are provided only
00030 with a limited warranty and the software's author, the holder of the
00031 economic rights, and the successive licensors have only limited
00032 liability. 
00033 
00034 In this respect, the user's attention is drawn to the risks associated
00035 with loading, using, modifying and/or developing or reproducing the
00036 software by the user in light of its specific status of free software,
00037 that may mean that it is complicated to manipulate, and that also
00038 therefore means that it is reserved for developers and experienced
00039 professionals having in-depth computer knowledge. Users are therefore
00040 encouraged to load and test the software's suitability as regards their
00041 requirements in conditions enabling the security of their systems and/or 
00042 data to be ensured and, more generally, to use and operate it in the 
00043 same conditions as regards security. 
00044 
00045 The fact that you are presently reading this means that you have had
00046 knowledge of the CeCILL license and that you accept its terms.
00047 
00048 LICENSE END */
00049 
00050 
00051 
00052 
00053 
00054 
00055 
00056 #include <classif.h>
00057 
00059 void
00060 class_days_pc_clusters(int *days_class_cluster, double *pc_eof_days, double *eof_days_cluster, char *type,
00061                        int neof, int ncluster, int ndays) {
00072   double dist_min; /* Minimum distance found between a given day PC (summed over all EOF) and each cluster centroid. */
00073   int clust_dist_min; /* Cluster number which has the minimum distance dist_min */
00074   double dist_sum; /* Sum of distances (partial computation) over all EOFs */
00075   double val; /* Distance between a given day PC (for a particular EOF) and one cluster centroid. */
00076   double dist_clust; /* Distance (full computation of dist_sum). */
00077   
00078   int day; /* Loop counter for days */
00079   int clust; /* Loop counter for cluster */
00080   int eof; /* Loop counter for eofs */
00081 
00082   if ( !strcmp(type, "euclidian") ) {
00083     /* Euclidian distance type */
00084 
00085     /* Parse each day */
00086     for (day=0; day<ndays; day++) {
00087 
00088       /* Initialize */
00089       dist_min = 9999999999.0;
00090       clust_dist_min = 999;
00091 
00092 #if DEBUG >= 7
00093       (void) fprintf(stderr, "day=%d\n", day);
00094 #endif
00095 
00096       /* Parse each cluster */
00097       for (clust=0; clust<ncluster; clust++) {
00098 
00099 #if DEBUG >= 7
00100         (void) fprintf(stderr, "clust=%d\n", clust);
00101 #endif
00102 
00103         dist_sum = 0.0;
00104         /* Sum all distances (over EOF) between the PC of the day and the PC of the cluster centroid for each EOF respectively */
00105         for (eof=0; eof<neof; eof++) {
00106           val = pc_eof_days[day+eof*ndays] - eof_days_cluster[eof+clust*neof];
00107 #if DEBUG >= 9
00108           printf("%d %d %lf %lf\n",clust,eof,pc_eof_days[day+eof*ndays],eof_days_cluster[eof+clust*neof]);
00109 #endif
00110           /* Euclidian distance: square */
00111           dist_sum += (val * val);
00112         }
00113         /* Euclidian distance: square root of squares */
00114         dist_clust = sqrt(dist_sum);
00115 
00116 #if DEBUG >= 7
00117         (void) fprintf(stderr, "dist_clust=%lf\n", dist_clust);
00118 #endif
00119 
00120         /* Is it a cluster which has less distance as the minimum found yet ? */
00121         if (dist_clust < dist_min) {
00122           /* Save cluster number */
00123           clust_dist_min = clust;
00124           dist_min = dist_clust;
00125         }
00126       }
00127       if (clust_dist_min == 999) {
00128         /* Failing algorithm */
00129         (void) fprintf(stderr, "%s: ABORT: Impossible: no cluster was selected!! Problem in algorithm...\n", __FILE__);
00130         (void) abort();
00131       }
00132       /* Assign cluster with minimum distance to all EOFs for this day */
00133       days_class_cluster[day] = clust_dist_min;
00134 #if DEBUG >= 9
00135       (void) fprintf(stderr, "%s: day %d cluster %d\n", __FILE__, day, clust_dist_min);
00136 #endif
00137     }
00138   }
00139   else {
00140     /* Unknown distance type */
00141     (void) fprintf(stderr, "%s: ABORT: Unknown distance type=%s!!\n", __FILE__, type);
00142     (void) abort();
00143   }
00144 }

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