public void PartitionOfUnity()
{
var k = new double[] { 0, 0, 0, 1, 2, 3, 4, 4, 5, 5, 5 };
Func <int, int, Func <double, double> > N = (i, p) => BSpline.Basis(k, i: i, p: p);
var us = Generate.LinearSpaced(100, 0, 4.9999);
var p = 2;
var order = p + 1;
foreach (var u in us)
{
var i = BSpline.KnotSpanFor(k, u);
Enumerable.Range(i - p, order).Sum(j => N(j, p)(u)).Should().BeApproximately(1.0, 1e-5);
}
}
public void BSplineKnotSearchShortWork()
{
{
var k = new double[] { 0, 0, 0, 1, 2, 3, 4, 4, 5, 5, 5 };
BSpline.KnotSpanFor(k, 0).Should().Be(2);
BSpline.KnotSpanFor(k, 0.5).Should().Be(2);
BSpline.KnotSpanFor(k, 1).Should().Be(3);
BSpline.KnotSpanFor(k, 2).Should().Be(4);
BSpline.KnotSpanFor(k, 5).Should().Be(10);
}
{
var k = new double[] { 0, 0, 1, 1 };
BSpline.KnotSpanFor(k, 0).Should().Be(1);
BSpline.KnotSpanFor(k, 0.5).Should().Be(1);
BSpline.KnotSpanFor(k, 1).Should().Be(3);
}
}