1 //===----------------------------------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 // <valarray>
11
12 // template<class T> class valarray;
13
14 // template<class T>
15 // valarray<T>
16 // atan2(const T& x, const valarray<T>& y);
17
18 #include <valarray>
19 #include <cassert>
20 #include <sstream>
21
is_about(double x,double y,int p)22 bool is_about(double x, double y, int p)
23 {
24 std::ostringstream o;
25 o.precision(p);
26 scientific(o);
27 o << x;
28 std::string a = o.str();
29 o.str("");
30 o << y;
31 return a == o.str();
32 }
33
main()34 int main()
35 {
36 {
37 typedef double T;
38 T a1[] = {-.9, -.5, 0., .5, .75};
39 T a3[] = {2.4468543773930902e+00,
40 2.1587989303424640e+00,
41 1.5707963267948966e+00,
42 9.8279372324732905e-01,
43 7.8539816339744828e-01};
44 const unsigned N = sizeof(a1)/sizeof(a1[0]);
45 std::valarray<T> v1(a1, N);
46 std::valarray<T> v3 = atan2(.75, v1);
47 assert(v3.size() == v1.size());
48 for (int i = 0; i < v3.size(); ++i)
49 assert(is_about(v3[i], a3[i], 10));
50 }
51 }
52