NuGet
Library can be also downloaded from nugetFeatures And Algorithms
Interpolation uses my own algorithm for calculating Lagrange coefficients. Approximation uses standard formula for building simultaneous equations and solves them using Gaussian elimination.Examples and usage
You can use this library to find function formula that goes through all given points. For example having {-2, 4}, {0, 0}, {1, 1} and {2, 4} we will receive f(x)=x^2 as result.// VARIABLES
List<PointD> points = new List<PointD>();
points.Add(new PointD(-2, 4));
points.Add(new PointD(0, 0));
points.Add(new PointD(1, 1));
points.Add(new PointD(2, 4));
//Computing
Interpolation interpolation = new Interpolation(points);
string result = interpolation.Compute();
Approximation returns function formula that goes near given points and is a polynomial of requested degree. For example approximation of {-4, 5}, {-2, 3}, {0, 1}, {2, 3}, {5, 5} requesting third degree will give us function as below:
// VARIABLES
int level = 3;
List<PointD> points = new List<PointD>();
points.Add(new PointD(-4, 5));
points.Add(new PointD(-2, 3));
points.Add(new PointD(0, 1));
points.Add(new PointD(2, 3));
points.Add(new PointD(5, 5));
//Computing
Approximation approximation = new Approximation(points, level);
string result = approximation.Compute();
Example application
Download: here