wls.m

rang doppler imaging and motion compensation中的源代码

function polyestim = wls(x,y,w,order)
% 
% Calculates polynomial estimates using weighted least squares fitting.
% x: Time coordinates of the measurements.
% y: Instananeous range measurements.
% w: Weight for the measurements. In this algorithm, the magnitude of
%    the segment is considered as weight.
%

     [m,n]=size(y);
     if m == 1
        m = n;
        n = 1;
        y = y(:);
     end

     [mm,nn]=size(x);
     if mm == 1
        mm = nn;
        nn = 1;
        x = x(:);
     end


     xvect=[];
     for ord = 0:order
     xpower=x.^ord;
     xvect=[xvect,xpower];
     end

     wmat=diag(w);
     polyest=inv(xvect'*wmat*xvect)*xvect'*wmat*y;
     polyestim=flipud(polyest);