c_reclass.c

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/*!
   \file cluster/c_reclass.c
 
   \brief Cluster library - Reclass data
 
   SPDX-FileCopyrightText: 2001-2009 GRASS Development Team
   SPDX-License-Identifier: GPL-2.0-or-later
 
   \author Original author CERL
 */
 
#include <grass/cluster.h>
 
/*!
   \brief Reclass data
 
   \param C pointer to Cluster structure
   \param minsize minimum class size
 
   \return 0 on success
   \return 1 no change
 */
int I_cluster_reclass(struct Cluster *C, int minsize)
{
    int band, c, hole, move, p;
 
    for (c = 0; c < C->nclasses; c++)
        C->reclass[c] = c;
 
    /* find first `empty' class */
    for (hole = 0; hole < C->nclasses; hole++)
        if (C->count[hole] < minsize)
            break;
 
    /* if none, just return */
    if (hole >= C->nclasses)
        return 1;
 
    for (move = hole; move < C->nclasses; move++)
        if (C->count[move] >= minsize) {
            C->reclass[move] = hole;
            C->count[hole] = C->count[move];
            for (band = 0; band < C->nbands; band++)
                C->sum[band][hole] = C->sum[band][move];
            hole++;
        }
        else
            C->reclass[move] = -1; /* eliminate this class */
 
    for (p = 0; p < C->npoints; p++)
        C->class[p] = C->reclass[C->class[p]];
    C->nclasses = hole;
 
    return 0;
}