Description of slcount

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slcount

PURPOSE

SLCOUNT Count the number of sum entities

SYNOPSIS

function [nums, U] = slcount(A)

DESCRIPTION

SLCOUNT Count the number of sum entities

 $ Syntax $
   - nums = slcount(A)
   - [nums, U] = slcount(A)

 $ Arguments $
   - A:          the array (or cell array) containing things to be count
   - nums:       the resultant column vector of numbers
   - U:          the column vector or column cell array containing
                 the unique instances

 $ Description $
   - nums = slcount(A) counts the numbers of each entity contained in A.

   - [nums, U] = slcount(A) counts the numbers of each entity, and return
     the unique instances of these entities in order via U. 

 $ Remarks $
   # The instances belonging to the same type should be put together.
   # A can be a numeric array or a cell array. For numeric arrays, we
     use = for comparison, for cell array, we use isequal for comparison.

 $ Examples $
   - Count elements in a numeric array,
     \{
          A = [1 1 1 2 2 2 3 3 1 1 1 1];
          [n, U] = slcount(A)

          n = 
               3
               3
               2
               4

          U =
               1
               2
               3
               1
     \}

   - Count elements in a cell array
     \{
          A = {'a', 'a', 'a', 'b', 'b'};
          [n, U] = slcount(A)

          n =
              3
              2

          U =
              'a'
              'b'
     \}

 $ History $
   - Created by Dahua Lin on Nov 19th, 2005

CROSS-REFERENCE INFORMATION

This function calls:

This function is called by:

• slcountvote SLCOUNTRULE Counts the votings to make histogram
• sledgeset2adjlist SLEDGESET2ADJLIST Converts edge set to adjacency list
• slpruneedgeset SLPRUNEEDGESET Prunes the edge set
• sllabelinds SLLABELINDS Extract indices corresponding to specified labels

SOURCE CODE

0001 function [nums, U] = slcount(A)
0002 %SLCOUNT Count the number of sum entities
0003 %
0004 % $ Syntax $
0005 %   - nums = slcount(A)
0006 %   - [nums, U] = slcount(A)
0007 %
0008 % $ Arguments $
0009 %   - A:          the array (or cell array) containing things to be count
0010 %   - nums:       the resultant column vector of numbers
0011 %   - U:          the column vector or column cell array containing
0012 %                 the unique instances
0013 %
0014 % $ Description $
0015 %   - nums = slcount(A) counts the numbers of each entity contained in A.
0016 %
0017 %   - [nums, U] = slcount(A) counts the numbers of each entity, and return
0018 %     the unique instances of these entities in order via U.
0019 %
0020 % $ Remarks $
0021 %   # The instances belonging to the same type should be put together.
0022 %   # A can be a numeric array or a cell array. For numeric arrays, we
0023 %     use = for comparison, for cell array, we use isequal for comparison.
0024 %
0025 % $ Examples $
0026 %   - Count elements in a numeric array,
0027 %     \{
0028 %          A = [1 1 1 2 2 2 3 3 1 1 1 1];
0029 %          [n, U] = slcount(A)
0030 %
0031 %          n =
0032 %               3
0033 %               3
0034 %               2
0035 %               4
0036 %
0037 %          U =
0038 %               1
0039 %               2
0040 %               3
0041 %               1
0042 %     \}
0043 %
0044 %   - Count elements in a cell array
0045 %     \{
0046 %          A = {'a', 'a', 'a', 'b', 'b'};
0047 %          [n, U] = slcount(A)
0048 %
0049 %          n =
0050 %              3
0051 %              2
0052 %
0053 %          U =
0054 %              'a'
0055 %              'b'
0056 %     \}
0057 %
0058 % $ History $
0059 %   - Created by Dahua Lin on Nov 19th, 2005
0060 %
0061 
0062 if nargout >= 2
0063     bU = true;
0064 else
0065     bU = false;
0066 end
0067 
0068 if isnumeric(A) % processing numeric array (vectorized code)
0069     A = A(:);
0070     difs = diff(A);
0071     n = length(A);
0072     nums = [0; find(difs ~= 0); n];
0073     if bU
0074         U = A(nums(2:end));
0075     end
0076     nums = diff(nums);
0077     
0078 elseif iscell(A) % processing cell array (non-vectorizable code)
0079     A = A(:);
0080     n = length(A);
0081     difs = false(n, 1);
0082     for i = 1 : n-1
0083         if ~isequal(A{i}, A{i+1})
0084             difs(i) = 1;
0085         end
0086     end
0087     difs(n) = 1;
0088     nums = [0; find(difs)];
0089     if bU
0090         U = A(nums(2:end));
0091     end
0092     nums = diff(nums);
0093     
0094 else
0095     error('sltoolbox:invalidtype', ...
0096         'A should be a numeric array or a cell array');
0097 end
0098     
0099     
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