Description of sllabelinds

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sllabelinds

PURPOSE

SLLABELINDS Extract indices corresponding to specified labels

SYNOPSIS

function Inds = sllabelinds(labels, labelset)

DESCRIPTION

SLLABELINDS Extract indices corresponding to specified labels

 $ Syntax $
   - Inds = sllabelinds(labels, labelset)

 $ Arguments $
   - labels:       The labels of samples
   - labelset:     The set of labels whose indices to be extracted
   - Inds:         The cell array of indices extracted for labelset

 $ Description $
   - Inds = sllabelinds(labels, labelset) extracts the indices 
     corresponding to the labels specified in labelset. Suppose the
     labelset is given by [l1, l2, ...], then Inds would be like
     {[i11, i12, ...], [i21, i22, ...], ...}, where [i11, i12, ...] is
     a row vector of indices corresponding to l1, so that 
     labels(i11) = labels(i12) = ... = l1.
   
 $ History $
   - Created by Dahua Lin, on Aug 31, 2006

CROSS-REFERENCE INFORMATION

This function calls:

• slcount SLCOUNT Count the number of sum entities
• slnums2bounds SLNUMS2BOUNDS Compute the index-boundaries from section sizes

This function is called by:

• slkmeans SLKMEANS Performs K-Means Clustering on samples
• sllabeledsum SLLABELEDSUM Sums the numbers according to labels

SOURCE CODE

0001 function Inds = sllabelinds(labels, labelset)
0002 %SLLABELINDS Extract indices corresponding to specified labels
0003 %
0004 % $ Syntax $
0005 %   - Inds = sllabelinds(labels, labelset)
0006 %
0007 % $ Arguments $
0008 %   - labels:       The labels of samples
0009 %   - labelset:     The set of labels whose indices to be extracted
0010 %   - Inds:         The cell array of indices extracted for labelset
0011 %
0012 % $ Description $
0013 %   - Inds = sllabelinds(labels, labelset) extracts the indices
0014 %     corresponding to the labels specified in labelset. Suppose the
0015 %     labelset is given by [l1, l2, ...], then Inds would be like
0016 %     {[i11, i12, ...], [i21, i22, ...], ...}, where [i11, i12, ...] is
0017 %     a row vector of indices corresponding to l1, so that
0018 %     labels(i11) = labels(i12) = ... = l1.
0019 %
0020 % $ History $
0021 %   - Created by Dahua Lin, on Aug 31, 2006
0022 %
0023 
0024 %% parse and verify input
0025 
0026 if ~isvector(labels) || ~isnumeric(labels)
0027     error('sltoolbox:invalidarg', ...
0028         'labels should be a numeric vector');
0029 end
0030 
0031 if size(labels, 1) ~= 1
0032     labels = labels(:)';
0033 end
0034 
0035 %% re-arrange
0036 
0037 [labels, si] = sort(labels, 2, 'ascend');
0038 [nums, labelfound] = slcount(labels);
0039 [sinds, einds] = slnums2bounds(nums);
0040 [sfound, smap] = ismember(labelset, labelfound);
0041 
0042 %% extract
0043 
0044 c = length(labelset);
0045 Inds = cell(1, c);
0046 for i = 1 : c
0047     if sfound(i)
0048         mi = smap(i);
0049         curinds = si(sinds(mi):einds(mi));
0050         Inds{i} = curinds;
0051     else
0052         Inds{i} = [];
0053     end
0054 end
0055 
0056 
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0059 
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0061

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