reduce_connection

 --- reduce connection vertex
   [V, id] = reduce_connection(d, p);
 --- path coordinate for n-th connection
  d.Vc{n} : vertex coordinates along n-th connection path 
 --- pair of vetex index for n-th connection
  d.I_from(n)   : start vertex index
  d.I_to(n)     : end vertex index
 --- skip parameter
  p.Nskip = skip number for connections selection
  p.Nstep = skip number along path (neighbor distance= Nstep*0.2mm)
 --- output: reduced connection vertex
 V{n} : vertex 3D coordinate for n-th connections [Np x 3]
  id.I_from(n)   : start vertex index for n-th connection
  id.I_to(n)     : end vertex index for n-th connection

 2014-11-10 Masa-aki Sato

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

0001 function    [V, id] = reduce_connection(d, p);
0002 % --- reduce connection vertex
0003 %   [V, id] = reduce_connection(d, p);
0004 % --- path coordinate for n-th connection
0005 %  d.Vc{n} : vertex coordinates along n-th connection path
0006 % --- pair of vetex index for n-th connection
0007 %  d.I_from(n)   : start vertex index
0008 %  d.I_to(n)     : end vertex index
0009 % --- skip parameter
0010 %  p.Nskip = skip number for connections selection
0011 %  p.Nstep = skip number along path (neighbor distance= Nstep*0.2mm)
0012 % --- output: reduced connection vertex
0013 % V{n} : vertex 3D coordinate for n-th connections [Np x 3]
0014 %  id.I_from(n)   : start vertex index for n-th connection
0015 %  id.I_to(n)     : end vertex index for n-th connection
0016 %
0017 % 2014-11-10 Masa-aki Sato
0018 %
0019 % Copyright (C) 2011, ATR All Rights Reserved.
0020 % License : New BSD License(see VBMEG_LICENSE.txt)
0021 
0022 
0023 % number of connections
0024 NC = length(d.Vc);
0025 
0026 % skip selection for connections
0027 nlist = 1:p.Nskip:NC;
0028 
0029 % --- pair of vetex index for n-th connection
0030 id.I_from = d.I_from(nlist);
0031 id.I_to   = d.I_to(nlist)  ;
0032 
0033 N = length(nlist);
0034 V = cell(N,1);
0035 
0036 for n=1:N
0037     NP = size(d.Vc{nlist(n)},1);
0038     
0039     if p.Nstep < NP
0040         % skip points along path
0041         V{n} = d.Vc{nlist(n)}(1:p.Nstep:NP,:);
0042         
0043         if mod(NP,p.Nstep)~=0
0044             V{n} = [V{n}; d.Vc{nlist(n)}(end,:)];
0045         end
0046     else
0047         V{n} = d.Vc{nlist(n)}([1,NP],:);
0048     end
0049     if size(V{n},1) < 2,
0050         fprintf('# of point=%d\n',size(V{n},1))
0051     end
0052 end