%% Interpolation of Coarsely Sampled Sine Function
% Define the sample points, x, and corresponding sample values, v.

x = 0:pi/4:2*pi; 
v = sin(x);

%
% Define the query points to be a finer sampling over the range of x.

xq = 0:pi/16:2*pi;

%
% Interpolate the function at the query points and plot the result.

figure
vq1 = interp1(x,v,xq);
plot(x,v,'o',xq,vq1,':.');
xlim([0 2*pi]);
title('(Default) Linear Interpolation');

%
% Now evaluate v at the same points using the 'spline' method.

figure
vq2 = interp1(x,v,xq,'spline');
plot(x,v,'o',xq,vq2,':.');
xlim([0 2*pi]);
title('Spline Interpolation');

% Copyright 2015 The MathWorks, Inc.