vb_load_cortex_area

 Load cortical vertex coordinate & normal vector specified by area_key
  [V ,xx] = vb_load_cortex_area(brainfile,areafile,area_key,mode)
 -- Input 
 brainfile : Brain file name
 --- Optional input
 areafile  : Area file name
 area_key  : area key
 mode = 0  : normal vector at the vertex
      = 1  : average normal vector in the neighbor of BV original brain
 --- Output
 V   : cortex vertex coordinate [Nvertex, 3]
 xx  : Normal vector to cortical surface [Nvertex, 3]

 Copyright (C) 2011, ATR All Rights Reserved.
 License : New BSD License(see VBMEG_LICENSE.txt)

0001 function    [V ,xx] = vb_load_cortex_area(brainfile,areafile,area_key,mode)
0002 % Load cortical vertex coordinate & normal vector specified by area_key
0003 %  [V ,xx] = vb_load_cortex_area(brainfile,areafile,area_key,mode)
0004 % -- Input
0005 % brainfile : Brain file name
0006 % --- Optional input
0007 % areafile  : Area file name
0008 % area_key  : area key
0009 % mode = 0  : normal vector at the vertex
0010 %      = 1  : average normal vector in the neighbor of BV original brain
0011 % --- Output
0012 % V   : cortex vertex coordinate [Nvertex, 3]
0013 % xx  : Normal vector to cortical surface [Nvertex, 3]
0014 %
0015 % Copyright (C) 2011, ATR All Rights Reserved.
0016 % License : New BSD License(see VBMEG_LICENSE.txt)
0017 
0018 if ~exist('mode','var'), mode = 0; end;
0019 
0020 load([brainfile],'V','xx');
0021 
0022 if mode == 1,
0023     xx = vb_cortex_normal_average(brainfile);
0024 end
0025 
0026 if ~exist('areafile','var') || ~exist('area_key','var'),
0027     return;
0028 end;
0029 
0030 %
0031 % select area
0032 %
0033 if ~isempty(areafile) && ~isempty(area_key)
0034     Area = vb_get_area([areafile], area_key);
0035     ix = Area.Iextract;
0036     V  = V(ix,:);
0037     xx = xx(ix,:);
0038 end
0039