36 lines
1.1 KiB
C++
36 lines
1.1 KiB
C++
// Example of using the GeographicLib::CircularEngine class
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#include <iostream>
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#include <exception>
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#include <vector>
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#include <GeographicLib/CircularEngine.hpp>
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#include <GeographicLib/SphericalHarmonic.hpp>
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using namespace std;
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using namespace GeographicLib;
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int main() {
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// This computes the same value as example-SphericalHarmonic.cpp using a
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// CircularEngine (which will be faster if many values on a circle of
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// latitude are to be found).
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try {
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using std::hypot;
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int N = 3; // The maxium degree
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double ca[] = {10, 9, 8, 7, 6, 5, 4, 3, 2, 1}; // cosine coefficients
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vector<double> C(ca, ca + (N + 1) * (N + 2) / 2);
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double sa[] = {6, 5, 4, 3, 2, 1}; // sine coefficients
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vector<double> S(sa, sa + N * (N + 1) / 2);
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double a = 1;
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SphericalHarmonic h(C, S, N, a);
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double x = 2, y = 3, z = 1, p = hypot(x, y);
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CircularEngine circ = h.Circle(p, z, true);
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double v, vx, vy, vz;
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v = circ(x/p, y/p, vx, vy, vz);
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cout << v << " " << vx << " " << vy << " " << vz << "\n";
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}
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catch (const exception& e) {
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cerr << "Caught exception: " << e.what() << "\n";
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return 1;
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}
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}
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