function m = pslope(x,y,p)
x = x-mean(x);
y = y-mean(y);
Sxx = norm(x,p)^2;
Sxy = (norm(x+y,p)^2-norm(x-y,p)^2)/4;
m = Sxy/Sxx;
function m = pslope(x,y,p)
x = x-mean(x);
y = y-mean(y);
Sxx = norm(x,p)^2;
Sxy = (norm(x+y,p)^2-norm(x-y,p)^2)/4;
m = Sxy/Sxx;