% Example 10-2: Interpolation

x = 0:1.0:5;
y = [1.0 -0.6242 -1.4707 3.2406 -0.7366 -6.3717];
xi = 0:0.1:5;
yilin = interp1(x, y, xi, 'linear');
yispl = interp1(x, y, xi, 'spline');
yipch = interp1(x, y, xi, 'pchip');
yfun = 1.5.^xi.*cos(2*xi);
subplot(1,3,1)
plot(x, y, 'o', xi, yfun, xi, yilin, '--');
title('Linear')
subplot(1,3,2)
plot(x, y, 'o', xi, yfun, xi, yispl, '--');
title('Cubic spline')
subplot(1,3,3)
plot(x, y, 'o', xi, yfun, xi, yipch, '--');
title('Pchip')
pause
clf