48 lines
1.8 KiB
C++
48 lines
1.8 KiB
C++
#include "interpolate.h"
|
|
|
|
using namespace std;
|
|
|
|
Vel bilinearinterpolate(const UVGrid &uvGrid, int time, double lat, double lon) {
|
|
double latStep = uvGrid.latStep();
|
|
double lonStep = uvGrid.lonStep();
|
|
int timeStep = uvGrid.timeStep();
|
|
|
|
int latIndex = (lat - uvGrid.lats[0]) / latStep;
|
|
int lonIndex = (lon - uvGrid.lons[0]) / lonStep;
|
|
int timeIndex = (time - uvGrid.times[0]) / timeStep;
|
|
|
|
double timeRatio = (static_cast<double>(time) - uvGrid.times[timeIndex]) / timeStep;
|
|
double latRatio = (lat - uvGrid.lats[latIndex]) / latStep;
|
|
double lonRatio = (lon - uvGrid.lons[lonIndex]) / lonStep;
|
|
|
|
Vel point = {0, 0};
|
|
for (int timeOffset = 0; timeOffset <= 1; timeOffset++) {
|
|
for (int latOffset = 0; latOffset <= 1; latOffset++) {
|
|
for (int lonOffset = 0; lonOffset <= 1; lonOffset++) {
|
|
auto vertex = uvGrid[
|
|
timeIndex + 1 < uvGrid.timeSize ? timeIndex + timeOffset : timeIndex,
|
|
latIndex + 1 < uvGrid.latSize ? latIndex + latOffset : latIndex,
|
|
lonIndex + 1 < uvGrid.lonSize ? lonIndex + lonOffset : lonIndex
|
|
];
|
|
|
|
double timeRation = (1 - timeOffset) * (1 - timeRatio) + timeOffset * timeRatio;
|
|
double latRation = (1 - latOffset) * (1 - latRatio) + latOffset * latRatio;
|
|
double lonRation = (1 - lonOffset) * (1 - lonRatio) + lonOffset * lonRatio;
|
|
point += timeRation * latRation * lonRation * vertex;
|
|
}
|
|
}
|
|
}
|
|
|
|
return point;
|
|
}
|
|
|
|
vector<Vel> bilinearinterpolation(const UVGrid &uvGrid, vector<tuple<int, double, double>> points) {
|
|
vector<Vel> result;
|
|
result.reserve(points.size());
|
|
for (auto [time, lat, lon]: points) {
|
|
result.push_back(bilinearinterpolate(uvGrid, time, lat, lon));
|
|
}
|
|
|
|
return result;
|
|
}
|