/*static void Main(string[] args)
{
//TestTdm();
TestSplineOnWikipediaExample();
//TestSpline();
//TestPerf();
}*/
private static void TestSpline()
{
int n = 6;
// Create the data to be fitted
float[] x = new float[n];
float[] y = new float[n];
Random rand = new Random(1);
for (int i = 0; i < n; i++)
{
x[i] = i;
y[i] = (float)rand.NextDouble() * 10;
}
// Compute the x values that we will evaluate the spline at.
// Upsample the original data by a const factor.
int upsampleFactor = 10;
int nInterpolated = n * upsampleFactor;
float[] xs = new float[nInterpolated];
for (int i = 0; i < nInterpolated; i++)
{
xs[i] = (float)i * (n - 1) / (float)(nInterpolated - 1);
}
CubicSpline spline = new CubicSpline();
float[] ys = spline.FitAndEval(x, y, xs, true);
string path = @"..\..\testSpline.png";
//PlotSplineSolution("Cubic Spline Interpolation - Random Data", x, y, xs, ys, path);
}
private static void TestPerf()
{
int n = 10000;
// Create the data to be fitted
float[] x = new float[n];
float[] y = new float[n];
Random rand = new Random(1);
for (int i = 0; i < n; i++)
{
x[i] = i;
y[i] = (float)rand.NextDouble() * 10;
}
// Compute the x values that we will evaluate the spline at.
// Upsample the original data by a const factor.
int upsampleFactor = 10;
int nInterpolate = n * upsampleFactor;
float[] xs = new float[nInterpolate];
for (int i = 0; i < nInterpolate; i++)
{
xs[i] = (float)i / upsampleFactor;
}
// For perf, test multiple reps
int reps = 100;
DateTime start = DateTime.Now;
for (int i = 0; i < reps; i++)
{
CubicSpline spline = new CubicSpline();
float[] ys = spline.FitAndEval(x, y, xs, false);
}
TimeSpan duration = DateTime.Now - start;
Console.WriteLine("CubicSpline upsample from {0:n0} to {1:n0} points took {2:0.00} ms for {3} iterations ({2:0.000} ms per iteration)",
n, nInterpolate, duration.TotalMilliseconds, reps, duration.TotalMilliseconds / reps);
// Compare to NRinC
//float[] y2 = new float[n];
//float[] ys2 = new float[nInterpolate];
//start = DateTime.Now;
//for (int i = 0; i < reps; i++)
//{
// CubicSplineNR.Spline(x, y, y2);
// CubicSplineNR.EvalSpline(x, y, y2, xs, ys2);
//}
//duration = DateTime.Now - start;
//Console.WriteLine("CubicSplineNR upsample from {0:n0} to {1:n0} points took {2:0.00} ms for {3} iterations ({2:0.000} ms per iteration)",
// n, nInterpolate, duration.TotalMilliseconds, reps, duration.TotalMilliseconds / reps);
}
/// <summary>
/// This is the Wikipedia "Spline Interpolation" article example.
/// </summary>
private static void TestSplineOnWikipediaExample()
{
// Create the test points.
float[] x = new float[] { -1.0f, 0.0f, 3.0f };
float[] y = new float[] { 0.5f, 0.0f, 3.0f };
Console.WriteLine("x: {0}", ArrayUtil.ToString(x));
Console.WriteLine("y: {0}", ArrayUtil.ToString(y));
// Create the upsampled X values to interpolate
int n = 20;
float[] xs = new float[n];
float stepSize = (x[x.Length - 1] - x[0]) / (n - 1);
for (int i = 0; i < n; i++)
{
xs[i] = x[0] + i * stepSize;
}
// Solve
CubicSpline spline = new CubicSpline();
float[] ys = spline.FitAndEval(x, y, xs, false);
Console.WriteLine("xs: {0}", ArrayUtil.ToString(xs));
Console.WriteLine("ys: {0}", ArrayUtil.ToString(ys));
// Plot
string path = @"..\..\spline-wikipedia.png";
//PlotSplineSolution("Cubic Spline Interpolation - Wikipedia Example", x, y, xs, ys, path);
}
