Description of edl_buildiidxdict

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edl_buildiidxdict

PURPOSE

EDL_BUILDIIDXDICT Builds a dictionary using internal index

SYNOPSIS

function Dict = edl_buildiidxdict(S, idxfn)

DESCRIPTION

EDL_BUILDIIDXDICT Builds a dictionary using internal index

 $ Syntax $
   - Dict = edl_buildiidxdict(S, idxfn)

 $ Arguments $
   - S:        a struct array on which the dictionary is built
   - idxfn:    the field name of the internal index 
               (default = 'internal_index')
   - Dict:     the built dictionary
               a cell array, indexed by internal_index

 $ Remarks $
   - The length of the cell array (dict) will be equal to the maximum
     internal index in S.
   - In S, different elements should have different internal indices.
   - For the index corresponding to no element, the corresponding cells
     are empty.
   - The dictionary will not automatically keep track of the change of
     S. If S is changed, the dictonary should be rebuilt in order to
     reflect the updates.

 $ History $
   - Created by Dahua Lin, on Aug 15, 2006

CROSS-REFERENCE INFORMATION

This function calls:

This function is called by:

SOURCE CODE

0001 function Dict = edl_buildiidxdict(S, idxfn)
0002 %EDL_BUILDIIDXDICT Builds a dictionary using internal index
0003 %
0004 % $ Syntax $
0005 %   - Dict = edl_buildiidxdict(S, idxfn)
0006 %
0007 % $ Arguments $
0008 %   - S:        a struct array on which the dictionary is built
0009 %   - idxfn:    the field name of the internal index
0010 %               (default = 'internal_index')
0011 %   - Dict:     the built dictionary
0012 %               a cell array, indexed by internal_index
0013 %
0014 % $ Remarks $
0015 %   - The length of the cell array (dict) will be equal to the maximum
0016 %     internal index in S.
0017 %   - In S, different elements should have different internal indices.
0018 %   - For the index corresponding to no element, the corresponding cells
0019 %     are empty.
0020 %   - The dictionary will not automatically keep track of the change of
0021 %     S. If S is changed, the dictonary should be rebuilt in order to
0022 %     reflect the updates.
0023 %
0024 % $ History $
0025 %   - Created by Dahua Lin, on Aug 15, 2006
0026 %
0027 
0028 %% parse and verify input arguments
0029 
0030 if ~isstruct(S)
0031     error('sltoolbox:invalidarg', ...
0032         'The S should be a struct');
0033 end
0034 
0035 if nargin < 2 || isempty(idxfn)
0036     idxfn = 'internal_index';
0037 end
0038 
0039 if ~isfield(S, idxfn)
0040     error('sltoolbox:invalidarg', ...
0041         'The S have no specified internal index field');
0042 end
0043 
0044 %% Build dictionary
0045 
0046 % gather the internal indices
0047 n = numel(S);
0048 inds = zeros(n, 1);
0049 for i = 1 : n
0050     idx = S(i).(idxfn);
0051     if ischar(idx)
0052         idx = str2double(idx);
0053     end
0054     inds(i) = idx;
0055 end
0056 
0057 % construct dictionary
0058 m = max(inds);
0059 
0060 Dict = cell(m, 1);
0061 
0062 for i = 1 : n
0063     idx = inds(i);
0064     if ~isempty(Dict{idx})
0065         error('sltoolbox:rterror', ...
0066             'Repeated index %d is encountered', idx);
0067     end
0068     Dict{idx} = S(i);        
0069 end
0070

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