function [b,a,r,se2,sb2,sa2]=linearfit(x,y)

if numel(x)==1
    a=0; b=0; r=0;
end

n=length(x);
df=n-2;

xm=mean(x);
ym=mean(y);

xxm=mean(x.^2);
yym=mean(y.^2);
xym=mean(x.*y);

b=(xym-xm*ym)/(xxm-xm^2);

se2 = n/df*(yym-ym^2-b^2*(xxm-xm^2));
sb2 = 1/n*se2/(xxm-xm^2);
sa2 = 1/n*sb2*xxm;


a=ym-b*xm;
r=(xym-xm*ym)/sqrt((xxm-xm^2)*(yym-ym^2));