1 // Ceres Solver - A fast non-linear least squares minimizer
2 // Copyright 2016 Google Inc. All rights reserved.
3 // http://ceres-solver.org/
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are met:
7 //
8 // * Redistributions of source code must retain the above copyright notice,
9 // this list of conditions and the following disclaimer.
10 // * Redistributions in binary form must reproduce the above copyright notice,
11 // this list of conditions and the following disclaimer in the documentation
12 // and/or other materials provided with the distribution.
13 // * Neither the name of Google Inc. nor the names of its contributors may be
14 // used to endorse or promote products derived from this software without
15 // specific prior written permission.
16 //
17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21 // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 // POSSIBILITY OF SUCH DAMAGE.
28 //
29 // Authors: keir@google.com (Keir Mierle), dgossow@google.com (David Gossow)
30
31 #include "ceres/is_close.h"
32
33 #include <algorithm>
34 #include <cmath>
35
36 namespace ceres {
37 namespace internal {
IsClose(double x,double y,double relative_precision,double * relative_error,double * absolute_error)38 bool IsClose(double x,
39 double y,
40 double relative_precision,
41 double* relative_error,
42 double* absolute_error) {
43 double local_absolute_error;
44 double local_relative_error;
45 if (!absolute_error) {
46 absolute_error = &local_absolute_error;
47 }
48 if (!relative_error) {
49 relative_error = &local_relative_error;
50 }
51 *absolute_error = std::fabs(x - y);
52 *relative_error = *absolute_error / std::max(std::fabs(x), std::fabs(y));
53 if (x == 0 || y == 0) {
54 // If x or y is exactly zero, then relative difference doesn't have any
55 // meaning. Take the absolute difference instead.
56 *relative_error = *absolute_error;
57 }
58 return *relative_error < std::fabs(relative_precision);
59 }
60 } // namespace internal
61 } // namespace ceres
62