44 lines
1.3 KiB
C++
44 lines
1.3 KiB
C++
// Example of using the GeographicLib::GravityCircle class
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// This requires that the egm96 gravity model be installed; see
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// https://geographiclib.sourceforge.io/C++/doc/gravity.html#gravityinst
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#include <iostream>
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#include <exception>
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#include <GeographicLib/GravityModel.hpp>
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#include <GeographicLib/GravityCircle.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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try {
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GravityModel grav("egm96");
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double lat = 27.99, lon0 = 86.93, h = 8820; // Mt Everest
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{
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// Slow method of evaluating the values at several points on a circle of
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// latitude.
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for (int i = -5; i <= 5; ++i) {
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double lon = lon0 + i * 0.2;
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double gx, gy, gz;
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grav.Gravity(lat, lon, h, gx, gy, gz);
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cout << lon << " " << gx << " " << gy << " " << gz << "\n";
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}
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}
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{
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// Fast method of evaluating the values at several points on a circle of
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// latitude using GravityCircle.
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GravityCircle circ = grav.Circle(lat, h);
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for (int i = -5; i <= 5; ++i) {
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double lon = lon0 + i * 0.2;
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double gx, gy, gz;
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circ.Gravity(lon, gx, gy, gz);
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cout << lon << " " << gx << " " << gy << " " << gz << "\n";
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}
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}
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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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