function [M,err] = fadd_lsq(phi,m,n)
% least-squares additive approx to Lip. func phi
global Lmf
global myopt
if isempty(Lmf)
  Lmf = getLmf(m,n);
else
  [a,b] = size(Lmf);
  if ~( (a==m^n) & (b==m*n) )
    Lmf = getLmf(m,n);
  end
end

H = Lmf'*Lmf;
f = - phi*Lmf;

x = quadprog(H,f,[],[],[],[],0*phi',0*phi'+n,[],myopt);
M = reshape(x,[m n]);

err = sum(abs(Lmf*x - phi'));
return