clear
clc
close all

x =[ 0 .8 2.3 3 3.9 5.2 6];
y = [-.2 -2 2.6 3.5 3.3 5.1 7.9];

plot(x, y, 'r+')
%axis([-1 7 -1 9])
interp1(x, y, 1.5)
interp1(y, x, 5)
xp = -1:.1:7
yp = interp1(x, y, xp)
hold on
plot(xp, yp, 'gs')
ysp = spline(x, y, xp);
plot(xp, ysp)