Smooth curves how to

Hi

got three data points and need to join them with smooth curve insted of a straight line.

please help.

commands below..

x=[1 2 3];
y=[1.22 3.31 1.91];
plot(x,y)
hold on
y1=[1.1 1.65 0.60];
plot(x,y1)
hold on
y2=[1.22 3.48 2.44];
plot(x,y2)
hold on
y3=[2.61 2.61 2.39];
plot(x,y3)
hold on
y4=[1.39 2.44 0.87]

y4 =[1.3900    2.4400    0.8700]

plot(x,y4)
hold on
y5=[0.57 0.65 0.28];
plot(x,y5)
hold on
z=[2.0 2.0 2.0];
plot(x,z)

Answer 1

[KSSV]

x=[1 2 3];
y=[1.22 3.31 1.91];
xx = min(x):0.1:max(x);
yy = spline(x,y,xx);
plot(x,y,'r',xx,yy,'b')