Goby3  3.1.5a
2024.05.23
sci.h
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1 // Copyright 2010-2021:
2 // GobySoft, LLC (2013-)
3 // Massachusetts Institute of Technology (2007-2014)
4 // Community contributors (see AUTHORS file)
5 // File authors:
6 // Toby Schneider <toby@gobysoft.org>
7 //
8 //
9 // This file is part of the Goby Underwater Autonomy Project Libraries
10 // ("The Goby Libraries").
11 //
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13 // them under the terms of the GNU Lesser General Public License as published by
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20 // GNU Lesser General Public License for more details.
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23 // along with Goby. If not, see <http://www.gnu.org/licenses/>.
24 
25 #ifndef GOBY_UTIL_SCI_H
26 #define GOBY_UTIL_SCI_H
27 
28 #include <cmath>
29 #include <map>
30 
31 namespace goby
32 {
33 namespace util
34 {
36 
37 
44 [[deprecated("use std::round() or dccl::round()")]] inline double unbiased_round(double r,
45  double dec)
46 {
47  double ex = std::pow(10.0, dec);
48  double final = std::floor(r * ex);
49  double s = (r * ex) - final;
50 
51  // remainder less than 0.5 or even number next to it
52  if (s < 0.5 || (s == 0.5 && !(static_cast<unsigned long>(final) & 1)))
53  return final / ex;
54  else
55  return (final + 1) / ex;
56 }
57 
59 inline unsigned ceil_log2(unsigned v)
60 {
61  // r will be one greater (ceil) if v is not a power of 2
62  unsigned r = ((v & (v - 1)) == 0) ? 0 : 1;
63  while (v >>= 1) r++;
64  return r;
65 }
66 
67 inline unsigned ceil_log2(double d) { return ceil_log2(static_cast<unsigned>(std::ceil(d))); }
68 
69 inline unsigned ceil_log2(int i) { return ceil_log2(static_cast<unsigned>(i)); }
70 
71 [[deprecated("use std::log2()")]] inline double log2(double d) { return std::log2(d); }
72 
78 template <typename N1, typename N2> N2 linear_interpolate(N1 a, const std::map<N1, N2>& table)
79 {
80  auto l_it = table.upper_bound(a);
81 
82  // clip to max value
83  if (l_it == table.end())
84  {
85  return (--l_it)->second;
86  }
87  // clip to min value
88  else if (l_it == table.begin())
89  {
90  return l_it->second;
91  }
92  // linear interpolation
93  else
94  {
95  auto u_it = l_it;
96  --l_it;
97  auto a_u = u_it->first, a_l = l_it->first;
98  auto b_u = u_it->second, b_l = l_it->second;
99  return static_cast<double>((a - a_l) / (a_l - a_u)) * (b_l - b_u) + b_l;
100  }
101 }
102 
103 } // namespace util
104 
106 
107 } // namespace goby
108 
109 #endif
goby
The global namespace for the Goby project.
Definition: acomms_constants.h:33
goby::util::ceil_log2
unsigned ceil_log2(unsigned v)
Definition: sci.h:59
goby::util::log2
double log2(double d)
Definition: sci.h:71
goby::util::linear_interpolate
N2 linear_interpolate(N1 a, const std::map< N1, N2 > &table)
Linear interpolation function.
Definition: sci.h:78
goby::util::unbiased_round
double unbiased_round(double r, double dec)
Definition: sci.h:44