1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// <valarray>
// template<class T> class valarray;
// template<class T>
// valarray<T>
// atan2(const valarray<T>& x, const T& y);
#include <valarray>
#include <cassert>
#include <sstream>
#include <cstddef>
bool is_about(double x, double y, int p)
{
std::ostringstream o;
o.precision(p);
scientific(o);
o << x;
std::string a = o.str();
o.str("");
o << y;
return a == o.str();
}
int main()
{
{
typedef double T;
T a1[] = {-.9, -.5, 0., .5, .75};
T a3[] = {-8.7605805059819342e-01,
-5.8800260354756750e-01,
0.0000000000000000e+00,
5.8800260354756750e-01,
7.8539816339744828e-01};
const unsigned N = sizeof(a1)/sizeof(a1[0]);
std::valarray<T> v1(a1, N);
std::valarray<T> v3 = atan2(v1, .75);
assert(v3.size() == v1.size());
for (std::size_t i = 0; i < v3.size(); ++i)
assert(is_about(v3[i], a3[i], 10));
}
}
|