53 lines
1.0 KiB
C
53 lines
1.0 KiB
C
/*
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* histo.c - Distribution of Z values
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*
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* Written 2010 by Werner Almesberger
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* Copyright 2010 by Werner Almesberger
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include "util.h"
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#include "array.h"
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#include "histo.h"
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struct histo *make_histo(struct array *a)
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{
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int i;
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struct histo *h;
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h = alloc_type(struct histo);
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h->n = a->max_z-a->min_z+1;
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h->b = alloc_size(h->n*sizeof(int));
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for (i = 0; i != h->n; i++)
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h->b[i] = 0;
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for (i = 0; i != (a->max_x-a->min_x+1)*(a->max_y-a->min_y+1); i++)
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if (a->data[i] != UNDEF)
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h->b[a->data[i]-a->min_z]++;
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return h;
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}
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void free_histo(struct histo *h)
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{
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free(h);
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}
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int median(const struct histo *h)
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{
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int tot = 0, sum = 0;
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int i;
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for (i = 0; i != h->n; i++)
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tot += h->b[i];
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for (i = 0; sum < tot/2; i++)
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sum += h->b[i];
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return i-1;
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}
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