vb_index2indexsub

 Transform absolute index to relative index
 -- Syntax
 [jx] = vb_index2indexsub(ix, ixsub)
 [jx, ix_in_ixsub] = vb_index2indexsub(ix, ixsub)
 -- Input 
 ix    : target indices to be transformed
 ixsub : indices of sub-region

 -- Output
 Transform absolute index to index within 'ixsub'
 jx          : transformed indices w.r.t 'ixsub'
 ix_in_ixsub : absolute index included in both 'ixsub' & 'ix' 
               vertex index in 'ix' which is included in 'ixsub'
 ix_in_ixsub = ixsub(jx)

 Example.
 ix=[1 5 10], ixsub=[5:10],
 --> jx = [1 6] 
     ix_in_ixsub = [5 10]

 Modufied by M. Sato 2006/8/20
   Input argument 'Nall' is removed.
   Nall is automatically calculated.

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

0001 function    [jx, ix_in_ixsub]= vb_index2indexsub(ix, ixsub)
0002 % Transform absolute index to relative index
0003 % -- Syntax
0004 % [jx] = vb_index2indexsub(ix, ixsub)
0005 % [jx, ix_in_ixsub] = vb_index2indexsub(ix, ixsub)
0006 % -- Input
0007 % ix    : target indices to be transformed
0008 % ixsub : indices of sub-region
0009 %
0010 % -- Output
0011 % Transform absolute index to index within 'ixsub'
0012 % jx          : transformed indices w.r.t 'ixsub'
0013 % ix_in_ixsub : absolute index included in both 'ixsub' & 'ix'
0014 %               vertex index in 'ix' which is included in 'ixsub'
0015 % ix_in_ixsub = ixsub(jx)
0016 %
0017 % Example.
0018 % ix=[1 5 10], ixsub=[5:10],
0019 % --> jx = [1 6]
0020 %     ix_in_ixsub = [5 10]
0021 %
0022 % Modufied by M. Sato 2006/8/20
0023 %   Input argument 'Nall' is removed.
0024 %   Nall is automatically calculated.
0025 %
0026 % Copyright (C) 2011, ATR All Rights Reserved.
0027 % License : New BSD License(see VBMEG_LICENSE.txt)
0028 
0029 Nsub = length(ixsub);
0030 Nall = max([ ix(:); ixsub(:) ]);
0031 
0032 Itrans          = zeros(Nall,1);
0033 Itrans(ixsub) = 1:Nsub;
0034 
0035 jx_tmp = Itrans(ix); 
0036 jx = find(jx_tmp > 0);
0037 jx = jx_tmp(jx);
0038 
0039 ix_in_ixsub = ixsub(jx);