| /* |
| * Implement Heap sort -- direct and indirect sorting |
| * Based on descriptions in Sedgewick "Algorithms in C" |
| * |
| * Copyright (C) 1999 Thomas Walter |
| * |
| * 18 February 2000: Modified for GSL by Brian Gough |
| * |
| * This is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License as published by the |
| * Free Software Foundation; either version 2, or (at your option) any |
| * later version. |
| * |
| * This source is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * for more details. |
| */ |
| |
| static inline void FUNCTION (my, downheap) (BASE * data, const size_t stride, const size_t N, size_t k); |
| |
| static inline void |
| FUNCTION (my, downheap) (BASE * data, const size_t stride, const size_t N, size_t k) |
| { |
| BASE v = data[k * stride]; |
| |
| while (k <= N / 2) |
| { |
| size_t j = 2 * k; |
| |
| if (j < N && data[j * stride] < data[(j + 1) * stride]) |
| { |
| j++; |
| } |
| |
| if (!(v < data[j * stride])) /* avoid infinite loop if nan */ |
| { |
| break; |
| } |
| |
| data[k * stride] = data[j * stride]; |
| |
| k = j; |
| } |
| |
| data[k * stride] = v; |
| } |
| |
| void |
| TYPE (gsl_sort) (BASE * data, const size_t stride, const size_t n) |
| { |
| size_t N; |
| size_t k; |
| |
| if (n == 0) |
| { |
| return; /* No data to sort */ |
| } |
| |
| /* We have n_data elements, last element is at 'n_data-1', first at |
| '0' Set N to the last element number. */ |
| |
| N = n - 1; |
| |
| k = N / 2; |
| k++; /* Compensate the first use of 'k--' */ |
| do |
| { |
| k--; |
| FUNCTION (my, downheap) (data, stride, N, k); |
| } |
| while (k > 0); |
| |
| while (N > 0) |
| { |
| /* first swap the elements */ |
| BASE tmp = data[0 * stride]; |
| data[0 * stride] = data[N * stride]; |
| data[N * stride] = tmp; |
| |
| /* then process the heap */ |
| N--; |
| |
| FUNCTION (my, downheap) (data, stride, N, 0); |
| } |
| } |
| |
| void |
| TYPE (gsl_sort_vector) (TYPE (gsl_vector) * v) |
| { |
| TYPE (gsl_sort) (v->data, v->stride, v->size) ; |
| } |
| |