This example shows how to interpolate data with a cubic spline in 2 dimensions. It uses the MATLAB SPLINE function. It does NOT use the Curve Fitting Toolbox™ spline functions, which are a complete set of functions for B-splines and other piecewise polynomials of any degree.
Randomly pick eight points. Plot them.
n = 8; x = rand(n,1); y = rand(n,1); plot(x,y,'.') axis([0 1 0 1])
Interpolate the points with two splines by evaluating them with a finer spacing. Plot the interpolated curve with a red line.
t = 1:n; ts = 1:1/10:n; xs = spline(t,x,ts); ys = spline(t,y,ts); hold on plot(xs,ys,'r'); hold off