public void Test_NaturalSpline_ValuesMatch()
{
double[] xs = { 0, 10, 20, 30 };
double[] ys = { 65, 25, 55, 80 };
var nsi = new ScottPlot.Statistics.Interpolation.NaturalSpline(xs, ys, resolution: 20);
var psi = new ScottPlot.Statistics.Interpolation.PeriodicSpline(xs, ys, resolution: 20);
var esi = new ScottPlot.Statistics.Interpolation.EndSlopeSpline(xs, ys, resolution: 20);
// verify output values have not deviated frrom what is expected
Assert.AreEqual(-1752748231, ScottPlot.Tools.SimpleHash(nsi.interpolatedXs));
Assert.AreEqual(-1060440570, ScottPlot.Tools.SimpleHash(nsi.interpolatedYs));
Assert.AreEqual(-1752748231, ScottPlot.Tools.SimpleHash(psi.interpolatedXs));
Assert.AreEqual(-351909896, ScottPlot.Tools.SimpleHash(psi.interpolatedYs));
Assert.AreEqual(-1752748231, ScottPlot.Tools.SimpleHash(esi.interpolatedXs));
Assert.AreEqual(-2040768015, ScottPlot.Tools.SimpleHash(esi.interpolatedYs));
var plt = new ScottPlot.Plot();
plt.PlotScatter(xs, ys, Color.Black, markerSize: 10, lineWidth: 0, label: "Original Data");
plt.PlotScatter(nsi.interpolatedXs, nsi.interpolatedYs, Color.Red, markerSize: 3, label: "Natural Spline");
plt.PlotScatter(psi.interpolatedXs, psi.interpolatedYs, Color.Green, markerSize: 3, label: "Periodic Spline");
plt.PlotScatter(esi.interpolatedXs, esi.interpolatedYs, Color.Blue, markerSize: 3, label: "End Slope Spline");
plt.Legend();
TestTools.SaveFig(plt);
}
public void ExecuteRecipe(Plot plt)
{
// create a small number of X/Y data points and display them
double[] xs = { 0, 10, 20, 30 };
double[] ys = { 65, 25, 55, 80 };
plt.AddScatter(xs, ys, Color.Black, markerSize: 10, lineWidth: 0, label: "Original Data");
// Calculate the interpolated splines using three different methods:
// Natural splines are "stiffer" than a polynomial interpolations and are less likely to oscillate.
// Periodic splines are natural splines whose first and last point slopes are matched.
// End slope splines let you define first and last data point slopes (defaults to zero).
var nsi = new ScottPlot.Statistics.Interpolation.NaturalSpline(xs, ys, resolution: 20);
var psi = new ScottPlot.Statistics.Interpolation.PeriodicSpline(xs, ys, resolution: 20);
var esi = new ScottPlot.Statistics.Interpolation.EndSlopeSpline(xs, ys, resolution: 20);
// plot the interpolated Xs and Ys
plt.AddScatter(nsi.interpolatedXs, nsi.interpolatedYs, Color.Red, markerSize: 3, label: "Natural Spline");
plt.AddScatter(psi.interpolatedXs, psi.interpolatedYs, Color.Green, markerSize: 3, label: "Periodic Spline");
plt.AddScatter(esi.interpolatedXs, esi.interpolatedYs, Color.Blue, markerSize: 3, label: "End Slope Spline");
plt.Legend();
}
