OR-Tools  8.2
lp_print_utils.h
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1// Copyright 2010-2018 Google LLC
2// Licensed under the Apache License, Version 2.0 (the "License");
3// you may not use this file except in compliance with the License.
4// You may obtain a copy of the License at
5//
6// http://www.apache.org/licenses/LICENSE-2.0
7//
8// Unless required by applicable law or agreed to in writing, software
9// distributed under the License is distributed on an "AS IS" BASIS,
10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11// See the License for the specific language governing permissions and
12// limitations under the License.
13
14// Utilities to display linear expression in a human-readable way.
15
16#ifndef OR_TOOLS_LP_DATA_LP_PRINT_UTILS_H_
17#define OR_TOOLS_LP_DATA_LP_PRINT_UTILS_H_
18
19#include <string>
20
21#include "absl/strings/str_format.h"
24
25namespace operations_research {
26namespace glop {
27
28// Returns a string representing a floating-point number in decimal,
29// with a precision corresponding to the type of the argument.
30inline std::string Stringify(const float a) {
31 return absl::StrFormat("%.7g", a);
32}
33
34inline std::string Stringify(const double a) {
35 return absl::StrFormat("%.16g", a);
36}
37
38inline std::string Stringify(const long double a) {
39 return absl::StrFormat("%.19g", a);
40}
41
42// Returns a string "num/den" representing the rational approximation of x.
43// The absolute difference between the output fraction and the input "x" will
44// not exceed "precision".
45std::string StringifyRational(const double x, const double precision);
46
47// If fraction is true, returns a string corresponding to the rational
48// approximation or a decimal approximation otherwise. Note that the absolute
49// difference between the output fraction and "x" will never exceed
50// std::numeric_limits<T>::epsilon().
51std::string Stringify(const Fractional x, bool fraction);
52
53// Pretty prints a monomial a*x using Stringify(x, fraction) to display a,
54// taking care of the sign of x, whether a is 0, 1, -1, integer. Note that the
55// absolute difference between the output fraction and "x" will never exceed
56// std::numeric_limits<T>::epsilon().
57std::string StringifyMonomial(const Fractional a, const std::string& x,
58 bool fraction);
59
60} // namespace glop
61} // namespace operations_research
62
63#endif // OR_TOOLS_LP_DATA_LP_PRINT_UTILS_H_
std::string StringifyMonomial(const Fractional a, const std::string &x, bool fraction)
std::string Stringify(const Fractional x, bool fraction)
std::string StringifyRational(const double x, const double precision)
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