Frobby 0.9.5
TermExtra.cpp
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1/* Frobby: Software for monomial ideal computations.
2 Copyright (C) 2007 Bjarke Hammersholt Roune (www.broune.com)
3 Copyright (C) 2010 University of Aarhus
4 Contact Bjarke Hammersholt Roune for license information (www.broune.com)
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see http://www.gnu.org/licenses/.
18*/
19#include "stdinc.h"
20#include "TermExtra.h"
21
22#include <algorithm>
23#include <vector>
24
25Exponent median(const Exponent* a, size_t varCount) {
26 if (varCount == 0)
27 return 0;
28
29 Term t(a, varCount);
30 Exponent* middle = t.begin() + varCount / 2;
31 nth_element(t.begin(), middle, t.end());
32 return *middle;
33}
34
35Exponent medianPositive(const Exponent* a, size_t varCount) {
36 vector<Exponent> exps;
37 exps.reserve(varCount);
38 for (size_t var = 0; var < varCount; ++var)
39 if (a[var] > 0)
40 exps.push_back(a[var]);
41 if (exps.empty())
42 return 0;
43
44 vector<Exponent>::iterator middle = exps.begin() + exps.size() / 2;
45 nth_element(exps.begin(), middle, exps.end());
46 return *middle;
47}
48
49void totalDegree(mpz_class& res, const Exponent* a, size_t varCount) {
50 res = a[0];
51 for (size_t var = 1; var < varCount; ++var)
52 res += a[var];
53}
54
55Exponent minimumPositive(const Exponent* a, size_t varCount) {
56 for (size_t var = 0; var < varCount; ++var) {
57 if (a[var] != 0) {
58 Exponent min = a[var];
59 for (; var < varCount; ++var)
60 if (a[var] != 0 && a[var] < min)
61 min = a[var];
62 return min;
63 }
64 }
65 return 0;
66}
67
68Exponent maximum(const Exponent* a, size_t varCount) {
69 Exponent max = 0;
70 for (size_t var = 0; var < varCount; ++var)
71 if (a[var] > max)
72 max = a[var];
73 return max;
74}
Exponent median(const Exponent *a, size_t varCount)
Returns the lower median exponent of a.
Definition TermExtra.cpp:25
Exponent medianPositive(const Exponent *a, size_t varCount)
Returns the lower median of the positive exponents of a.
Definition TermExtra.cpp:35
void totalDegree(mpz_class &res, const Exponent *a, size_t varCount)
Puts the sum of the entries of a into res.
Definition TermExtra.cpp:49
Exponent minimumPositive(const Exponent *a, size_t varCount)
Returns the smallest positive exponent of a.
Definition TermExtra.cpp:55
Exponent maximum(const Exponent *a, size_t varCount)
Returns the largest exponent of a.
Definition TermExtra.cpp:68
Term represents a product of variables which does not include a coefficient.
Definition Term.h:49
Exponent * begin()
Definition Term.h:79
Exponent * end()
Definition Term.h:82
This header file includes common definitions and is included as the first line of code in every imple...
unsigned int Exponent
Definition stdinc.h:89