squareGrid

SQUAREGRID Generate equally spaces points in plane.

   usage
   PTS = squareGrid(BOUNDS, ORIGIN, SIZE)
   generate points, lying in the window defined by BOUNDS (=[xmin ymin
   xmax ymax]), starting from origin with a constant step equal to size.
   
   Example
   PTS = squareGrid([0 0 10 10], [3 3], [4 2])
   will return points : 
   [3 1;7 1;3 3;7 3;3 5;7 5;3 7;7 7;3 9;7 9];



   TODO: add possibility to use rotated grid

   ---------

   author : David Legland 
   INRA - TPV URPOI - BIA IMASTE
   created the 06/08/2005.

0001 function varargout = squareGrid(bounds, origin, size)
0002 %SQUAREGRID Generate equally spaces points in plane.
0003 %
0004 %   usage
0005 %   PTS = squareGrid(BOUNDS, ORIGIN, SIZE)
0006 %   generate points, lying in the window defined by BOUNDS (=[xmin ymin
0007 %   xmax ymax]), starting from origin with a constant step equal to size.
0008 %
0009 %   Example
0010 %   PTS = squareGrid([0 0 10 10], [3 3], [4 2])
0011 %   will return points :
0012 %   [3 1;7 1;3 3;7 3;3 5;7 5;3 7;7 7;3 9;7 9];
0013 %
0014 %
0015 %
0016 %   TODO: add possibility to use rotated grid
0017 %
0018 %   ---------
0019 %
0020 %   author : David Legland
0021 %   INRA - TPV URPOI - BIA IMASTE
0022 %   created the 06/08/2005.
0023 %
0024 
0025 % find all x coordinate
0026 x1 = bounds(1) + mod(origin(1)-bounds(1), size(1));
0027 x2 = bounds(3) - mod(bounds(3)-origin(1), size(1));
0028 lx = (x1:size(1):x2)';
0029 
0030 % find all y coordinate
0031 y1 = bounds(2) + mod(origin(2)-bounds(2), size(2));
0032 y2 = bounds(4) - mod(bounds(4)-origin(2), size(2));
0033 ly = (y1:size(2):y2)';
0034 
0035 % number of points in each coord, and total number of points
0036 ny = length(ly);
0037 nx = length(lx);
0038 np = nx*ny;
0039 
0040 % create points
0041 pts = zeros(np, 2);
0042 for i=1:ny
0043     pts( (1:nx)'+(i-1)*nx, 1) = lx;
0044     pts( (1:nx)'+(i-1)*nx, 2) = ly(i);
0045 end    
0046 
0047 % process output
0048 if nargout>0
0049     varargout{1} = pts;
0050 end