www.gusucode.com > mbcexpr 工具箱 matlab 源码程序 > mbcexpr/@cglookuptwo/MaxGradient.m

    function [MaxChg,dx,dy]= MaxGradient(LT)
%MAXGRADIENT maximum gradient of lookup table
%
% [MaxChg,dx,dy]= MaxGradient(LT)

%  Copyright 2005 The MathWorks, Inc.

bp=get(LT,'axes');
bpx= bp{2};
bpy= bp{1};

V= LT.Values;
m= length(bpx);
n= length(bpy);

dx= diff(bpx);
dy= diff(bpy);

DefaultChg=[-1 1 -1 1];
DX= diff(V,[],1)./repmat(dx(:),1,n);
DY= diff(V,[],2)./repmat(dy(:)',m,1);
MaxChg = [min(DX(:)) max(DX(:)) min(DY(:)) max(DY(:))];
MaxChg(MaxChg==0)= DefaultChg(MaxChg==0);