c_distinct.c

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/*!
   \file cluster/c_distinct.c
 
   \brief Cluster library - Distinct value
 
   SPDX-FileCopyrightText: 2001-2009 GRASS Development Team
   SPDX-License-Identifier: GPL-2.0-or-later
 
   \author Original author CERL
 */
 
#include <grass/cluster.h>
 
/*!
   \brief Get distinct value
 
   \param C pointer to Cluster structure
   \param separation separation value
 
   \return distinction value
 */
int I_cluster_distinct(struct Cluster *C, double separation)
{
    int class1, class2;
    int distinct;
    double dmin;
    double dsep;
 
    /* compute sum of squares for each class */
    I_cluster_sum2(C);
 
    /* find closest classes */
    distinct = 1;
    dmin = separation;
    for (class1 = 0; class1 < (C->nclasses - 1); class1++) {
        if (C->count[class1] < 2)
            continue;
        for (class2 = class1 + 1; class2 < C->nclasses; class2++) {
            if (C->count[class2] < 2)
                continue;
            dsep = I_cluster_separation(C, class1, class2);
 
            if (dsep >= 0.0 && dsep < dmin) {
                distinct = 0;
                C->merge1 = class1;
                C->merge2 = class2;
                dmin = dsep;
            }
        }
    }
 
    return distinct;
}