Adding upstream version 16.2.11+ds.upstream/16.2.11+dsupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/src/boost/libs/math/example/catmull_rom_example.cpp b/src/boost/libs/math/example/catmull_rom_example.cpp
new file mode 100644
index 000000000..69a497070
--- /dev/null
+++ b/src/boost/libs/math/example/catmull_rom_example.cpp
@@ -0,0 +1,45 @@
+// Copyright Nick Thompson, 2017
+
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or
+// copy at http://www.boost.org/LICENSE_1_0.txt).
+
+#include <iostream>
+#include <vector>
+#include <array>
+#include <cmath>
+#include <boost/math/interpolators/catmull_rom.hpp>
+#include <boost/math/constants/constants.hpp>
+
+using std::sin;
+using std::cos;
+using boost::math::catmull_rom;
+
+int main()
+{
+    std::cout << "This shows how to use Boost's Catmull-Rom spline to create an Archimedean spiral.\n";
+
+    // The Archimedean spiral is given by r = a*theta. We have set a = 1.
+    std::vector<std::array<double, 2>> spiral_points(500);
+    double theta_max = boost::math::constants::pi<double>();
+    for (size_t i = 0; i < spiral_points.size(); ++i)
+    {
+        double theta = ((double) i/ (double) spiral_points.size())*theta_max;
+        spiral_points[i] = {theta*cos(theta), theta*sin(theta)};
+    }
+
+    auto archimedean = catmull_rom<std::array<double,2>>(std::move(spiral_points));
+    double max_s = archimedean.max_parameter();
+    std::cout << "Max s = " << max_s << std::endl;
+    for (double s = 0; s < max_s; s += 0.01)
+    {
+        auto p = archimedean(s);
+        double x = p[0];
+        double y = p[1];
+        double r = sqrt(x*x + y*y);
+        double theta = atan2(y/r, x/r);
+        std::cout << "r = " << r << ", theta = " << theta << ", r - theta = " << r - theta << std::endl;
+    }
+
+    return 0;
+}