pythag.m

求解离散病态问题的正则化方法matlab 工具箱

function x = pythag(y,z)
%PYTHAG Computes sqrt( y^2 + z^2 ).
%
% x = pythag(y,z)
%
% Returns sqrt(y^2 + z^2) but is careful to scale to avoid overflow.

% Christian H. Bischof, Argonne National Laboratory, 03/31/89.

rmax = max(abs([y;z]));
if (rmax==0)
  x = 0;
else
  x = rmax*sqrt((y/rmax)^2 + (z/rmax)^2);
end