% spline_data.m puts a cubic spline through a set of data points

D = [[2 1]; [5 9]; [7 6]; [12 0]];  % list of data points
x = D(:,1);                         % x values are 1st column of D
y = D(:,2);                         % y values are 2nd column of D

xi = min(x):.1:max(x);              % x values for interpolation
yi = spline(x,y,xi);                % interpolated y values

plot(x,y,'o',xi,yi)                 % plot data points and interpolated curve
title('Data points and cubic spline interpolation');
axis([min(xi)-1 max(xi)+1 min(yi)-1 max(yi)+1]);      % choose nice axes