X-Git-Url: http://git.tdb.fi/?p=libs%2Fmath.git;a=blobdiff_plain;f=source%2Finterpolate%2Flinearspline.h;fp=source%2Finterpolate%2Flinearspline.h;h=2c88cebbf4d784d774fb35263b5009b021fd1d18;hp=0000000000000000000000000000000000000000;hb=0d4dcdc1c4717c88e79dfd0b7d4ebe34ff7cc548;hpb=acdb569a0370162ffc282b2e43221f34e35e7c58

diff --git a/source/interpolate/linearspline.h b/source/interpolate/linearspline.h
new file mode 100644
index 0000000..2c88ceb
--- /dev/null
+++ b/source/interpolate/linearspline.h
@@ -0,0 +1,42 @@
+#ifndef MSP_INTERPOLATE_LINEARSPLINE_H_
+#define MSP_INTERPOLATE_LINEARSPLINE_H_
+
+#include <vector>
+#include "spline.h"
+
+namespace Msp {
+namespace Interpolate {
+
+/**
+A very simple type of spline.  It interpolates the value linearly between
+knots.
+*/
+template<typename T, unsigned N = 1>
+class LinearSpline: public Spline<T, 1, N>
+{
+public:
+	using typename Spline<T, 1, N>::Value;
+	using typename Spline<T, 1, N>::Knot;
+
+	LinearSpline(const std::vector<Knot> &k):
+		Spline<T, 1, N>(k.front())
+	{
+		typedef SplineValue<T, N> SV;
+
+		this->reserve(k.size()-1);
+		for(unsigned i=1; i<k.size(); ++i)
+		{
+			T dx = k[i].x-k[i-1].x;
+			Value slope = (k[i].y-k[i-1].y)/dx;
+			Polynomial<T, 1> p[N];
+			for(unsigned j=0; j<N; ++j)
+				p[j] = Polynomial<T, 1>(LinAl::Vector<T, 2>(SV::get(slope, j), SV::get(k[i-1].y, j)-k[i-1].x*SV::get(slope, j)));
+			this->add_segment(p, k[i].x);
+		}
+	}
+};
+
+} // namespace Interpolate
+} // namespace Msp
+
+#endif