clear all 
close all
%load some data
load linefit.dat
x=linefit(:,1);
y=linefit(:,2);
xx=0:.1:7;
plot(x,y,'.')

%polynomial fits
P1=polyfit(x,y,1);  %line fit
yy=polyval(P1,x);

P2=polyfit(x,y,2);   %quad fit
yy2=polyval(P2,x);

P10=polyfit(x,y,10);
yy10=polyval(P10,xx);

P11=polyfit(x,y,11);
yy11=polyval(P11,xx);

P14=polyfit(x,y,14);
yy14=polyval(P14,xx);

hold on
%plot(x,yy,'g',xx,yy11,'k')


%"connect the dots" interpolation

I1=interp1(x,y,xx);
plot(xx,I1,'g')
I2=interp1(x,y,xx,'nearest'); %step func
I3=interp1(x,y,xx,'spline');  %cubic spline
plot(xx,I2,'m')
plot(xx,I3,'k')