diff toolboxes/MIRtoolbox1.3.2/somtoolbox/vis_patch.m @ 0:e9a9cd732c1e tip

first hg version after svn

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolboxes/MIRtoolbox1.3.2/somtoolbox/vis_patch.m	Tue Feb 10 15:05:51 2015 +0000
@@ -0,0 +1,117 @@
+function p=vis_patch(lattice)
+
+% VIS_PATCH Defines the basic patches (hexa and rect) used in SOM_CPLANE
+%
+%  p = vis_patch(lattice)
+%
+%  Input and output arguments: 
+%   lattice   (string) 'rect', 'hexa' or 'hexagon'
+%
+%   p         (matrix) size Lx2, defines the vertices of the patch
+%
+% This function produces vertex coordinates for a patch presenting
+% a map unit in hexagonal or rectangular lattice with its centre in (0,0). 
+%
+% For more help, try 'type vis_patch' or check out online documentation.
+% See also SOM_CPLANE, PATCH.
+
+%%%% DETAILED DESCRIPTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% vis_patch
+%
+% SYNTAX
+%  
+%  p = vis_patch(lattice)
+% 
+% DESCRIPTION
+% 
+% Forms a map unit patch for SOM_CPLANE function. Mainly a subroutine
+% of SOM_CPLANE, although can be used for on its own as well.
+%
+% REQUIRED INPUT ARGUMENTS
+%
+% lattice (string)
+% 
+%    'hexa'  produces vertex coordiantes for a hexagoanl patch which 
+%            has its center on (0,0), unit width, and a height of
+%            1.3334 units. This is not a regular hexagon but such that
+%            the node which has topological coordinates (a,b) has its
+%            center in the visualization at coordinates (a,b) for odd
+%            a and at (a,b+.5) for even a. The non-regular look of the
+%            patch is taken care simply by changing the axis ratio.
+%
+%    'rect'  produces vertex coordinates for a uniform rectangular patch.
+%            having its center on (0,0) and unit sidelength. Used as a
+%            subfunction in SOM_CPLANE.
+%
+%    'hexagon' produces vertex coordinates for a regular hexagonal patch.
+%            It may be used in som_cplane if, for some reason, truly
+%            regular hexagons are needed instead of the default unit
+%            markers which are not uniform, but have integer
+%            y-coordinates in the lattice.
+%
+% OUTPUT ARGUMENTS
+%
+% p (matrix) The 2-dimensional vertex coordinates: 
+%
+%   case 'rect'        case 'hexa'                case 'hexagon'
+%    p=[[-.5 -.5];...     p=[[0     0.6667];...    p=[[0     0.5774];...
+%       [-.5  .5];...        [0.5   0.3333];...       [0.5   0.2887];...
+%       [ .5  .5];...        [0.5  -0.3333];...       [0.5  -0.2887];...
+%       [ .5 -.5]];          [0    -0.6667];...       [0    -0.5774];...
+%                            [-0.5 -0.3333];...       [-0.5 -0.2887];...
+%                            [-0.5  0.3333]];         [-0.5  0.2887]]; 
+%
+% EXAMPLES
+%
+%  som_cplane(vis_patch('rect'),[6 5],'none');
+%  % this produces the same result as som_cplane('rect',[6 5], 'none') 
+%  
+%  som_cplane(vis_patch('hexa'), vis_unit_coord('hexa',[6 5]), 'none');
+%  % produces in principle the same result as 
+%  % som_cplane(vis_patch('hexa'),[6 5],'none'), 
+%  % _but_ in this case the axis are not rescaled and the non-regular 
+%  % shape of hexagons can be seen.
+%
+%  som_cplane(vis_patch('hexagon'), som_unit_coords([6 5],'hexa'), 'none');
+%  % produces a truly regular hexa lattice 
+%
+% SEE ALSO 
+%
+%  vis_unit_coord   The default 'hexa' and 'rect' coordinates in visualizations
+%  som_unit_coords  Locations of units on the SOM grid.
+
+% Copyright (c) 1999-2000 by the SOM toolbox programming team.
+% http://www.cis.hut.fi/projects/somtoolbox/             
+
+% Version 2.0beta Johan 041099
+
+if ~ischar(lattice)
+  error('Input argument should be a string')
+else
+  switch lattice
+  case 'rect'
+    p=[[-.5 -.5]; ...
+      [-.5 .5];...
+      [.5 .5];...
+      [.5 -.5]];
+  case 'hexagon'
+    p=[[0 0.5774];...
+      [0.5 0.2887];...
+      [0.5 -0.2887];...
+      [0 -0.5774];...
+      [-0.5 -0.2887];...
+      [-0.5 0.2887]];
+  case 'hexa'
+    p=[[0 0.6667];...
+      [0.5 0.3333];...
+      [0.5 -0.3333];...
+      [0 -0.6667];...
+      [-0.5 -0.3333];...
+      [-0.5 0.3333]];
+  otherwise
+    error('Unknown lattice');
+  end
+end
+
+