lsst.meas.astrom g991b906543+cc4c7597ef
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polynomialUtils.cc
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1// -*- LSST-C++ -*-
2
3/*
4 * LSST Data Management System
5 * Copyright 2016 LSST/AURA
6 *
7 * This product includes software developed by the
8 * LSST Project (http://www.lsst.org/).
9 *
10 * This program is free software: you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation, either version 3 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the LSST License Statement and
21 * the GNU General Public License along with this program. If not,
22 * see <http://www.lsstcorp.org/LegalNotices/>.
23 */
24
25#include <mutex>
27
28namespace lsst {
29namespace meas {
30namespace astrom {
31namespace detail {
32
33void computePowers(Eigen::VectorXd& r, double x) {
34 r[0] = 1.0;
35 for (int i = 1; i < r.size(); ++i) {
36 r[i] = r[i - 1] * x;
37 }
38}
39
40Eigen::VectorXd computePowers(double x, int n) {
41 Eigen::VectorXd r(n + 1);
42 computePowers(r, x);
43 return r;
44}
45
46void BinomialMatrix::extend(int const n) {
47 static std::mutex mutex;
48 auto& old = getMatrix();
49 int const m = old.rows() - 1;
50 if (n <= m) return;
51 Eigen::MatrixXd updated = Eigen::MatrixXd::Zero(n + 1, n + 1);
52 updated.topLeftCorner(old.rows(), old.cols()) = old;
53 for (int i = m + 1; i <= n; ++i) {
54 updated(i, 0) = 1.0;
55 updated(i, i) = 1.0;
56 for (int j = 1; j < i; ++j) {
57 updated(i, j) = updated(i - 1, j - 1) * (static_cast<double>(i) / static_cast<double>(j));
58 }
59 }
61 old.swap(updated);
62}
63
64Eigen::MatrixXd& BinomialMatrix::getMatrix() {
65 static Eigen::MatrixXd it = Eigen::MatrixXd::Constant(2, 2, 1.0);
66 return it;
67}
68
69} // namespace detail
70} // namespace astrom
71} // namespace meas
72} // namespace lsst
double x
int m
void computePowers(Eigen::VectorXd &r, double x)
Fill an array with integer powers of x, so .