Update README.md

Author: Serophots

README.md

@@ -1,2 +1,47 @@
 # rbf-interpolation
-Radial basis function interpolation in Rust using nalgebra
+Radial basis function interpolation in Rust using nalgebra. Uses nightly rust in order to keep all matrix sizes known at compile time.
+
+# Example
+```rs
+use gnuplot::{AutoOption::Auto, AxesCommon, Figure, HELIX};
+use nalgebra::{Matrix, SMatrix, SVector, Vector2};
+use rbf_interpolation::builder::RBFInterpolatorBuilder;
+
+fn main() {
+    let points: SMatrix<f64, 2, 5> = Matrix::from_columns(&[
+        Vector2::new(2.0, 2.0),
+        Vector2::new(3.0, 4.0),
+        Vector2::new(6.0, 4.0),
+        Vector2::new(1.0, 1.0),
+        Vector2::new(7.0, 7.0),
+    ]);
+    let values = SVector::<f64, 5>::new(2.0, 6.0, 4.0, 4.0, 5.0);
+
+    let interpolant = RBFInterpolatorBuilder::<1, 3, 5, 2>::ThinPlateSpline
+        .build(points.clone(), values.clone())
+        .unwrap();
+
+    //15x15 with 0.1 resolution
+    let mut surface = Vec::with_capacity(150*150);
+    for i in 0..150 {
+        for j in 0..150 {
+            surface.push(interpolant.interpolate(&Vector2::new(i as f64 / 10.0, j as f64 / 10.0)));
+        }
+    }
+
+    let mut points = points.row_iter();
+
+    let mut fg = Figure::new();
+    fg.axes3d()
+        .set_title("Thin plate spline, 1 degree polynomial", &[])
+        .surface(surface, 150, 150, Some((0.0, 0.0, 15.0, 15.0)), &[])
+        .points(points.next().unwrap(), points.next().unwrap(), values.iter(), &[])
+        .set_x_label("X", &[])
+        .set_y_label("Y", &[])
+        .set_z_label("Z", &[])
+        .set_z_range(Auto, Auto)
+        .set_palette(HELIX)
+        .set_view(45.0, 175.0);
+    fg.show().unwrap();
+}
+```