cliplin2.m

很好用的统计模式识别工具箱

function [x,y]=cliplin2(alpha,window)
% [x,y]=cliplin2(alpha,window)
%
% CLIPLIN2 clips the line going from pixel [0,0] to pixel on
%   the border of the rectangle given by the argument window.
%   The direction of the line is given by the argument alpha.
%   This function returns coordinates of the mentioned pixel
%   on the border.
%
% See also CLIPLIN1.
%
% Statistical Pattern Recognition Toolbox, Vojtech Franc, Vaclav Hlavac
% (c) Czech Technical University Prague, http://cmp.felk.cvut.cz
% Written Vojtech Franc (diploma thesis) 12.10.1999
% Modifications
% 24. 6.00 V. Hlavac, comments polished.

% get window`s left side, right side, bottom...
minx=window(1);
maxx=window(2);
miny=window(3);
maxy=window(4);

if alpha(1) >= 0, ax = maxx; else ax = minx; end
if alpha(2) >= 0, ay = maxy; else ay = miny; end

if alpha(2) == 0,
   x = ax;
else
   x = alpha(1)*ay/alpha(2);
end

if alpha(1) == 0,
   y = ay;
else
   y = alpha(2)*ax/alpha(1);
end

if (x^2+ay^2) <= (ax^2+y^2),
   y = ay;
else
   x = ax;
end