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,coord_type)
 -- 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
 coord_type : = 'subj' : subject brain normal. 
              = 'std'  : standard brain normal(valid in BRAIN-MAT V2 format).
 --- 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, coord_type)
0002 % Load cortical vertex coordinate & normal vector specified by area_key
0003 %  [V, xx] = vb_load_cortex_area(brainfile,areafile,area_key,mode,coord_type)
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 % coord_type : = 'subj' : subject brain normal.
0012 %              = 'std'  : standard brain normal(valid in BRAIN-MAT V2 format).
0013 % --- Output
0014 % V   : cortex vertex coordinate [Nvertex, 3]
0015 % xx  : Normal vector to cortical surface [Nvertex, 3]
0016 %
0017 % Copyright (C) 2011, ATR All Rights Reserved.
0018 % License : New BSD License(see VBMEG_LICENSE.txt)
0019 
0020 if ~exist('mode','var'), mode = 0; end;
0021 
0022 if ~exist('coord_type', 'var')
0023     coord_type = 'subj';
0024 end
0025 
0026 if strcmp(coord_type, 'subj')
0027     [V, tmp, xx] = vb_load_cortex(brainfile, 'subj');
0028 else
0029     [V, tmp, xx] = vb_load_cortex(brainfile);
0030 end
0031 
0032 if mode == 1
0033     xx = vb_cortex_normal_average(brainfile,areafile,area_key,coord_type);
0034     return;
0035 end
0036 
0037 if ~exist('areafile','var') || ~exist('area_key','var'),
0038     return;
0039 end
0040 
0041 %
0042 % select area
0043 %
0044 if ~isempty(areafile) && ~isempty(area_key)
0045     Area = vb_get_area([areafile], area_key);
0046     ix = Area.Iextract;
0047     V  = V(ix,:);
0048     xx = xx(ix,:);
0049 end
0050