Description of slnums2bounds

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slnums2bounds

PURPOSE

SLNUMS2BOUNDS Compute the index-boundaries from section sizes

SYNOPSIS

function [spos, epos] = slnums2bounds(nums)

DESCRIPTION

SLNUMS2BOUNDS Compute the index-boundaries from section sizes

 $ Syntax $
   - [spos, epos] = slnums2bounds(nums)
   - spos = slnums2bounds(nums)

 $ Description $
   - [spos, epos] = slnums2bounds(nums) obtains the start positions and
     end positions of the sections given the number of elements in 
     the sections.

   - spos = slnums2bounds(nums) only retrieves the start positions.

 $ Reamrks $
   # nums can be either a row vector or a column vector. then the results
     will be row vector or column vector correspondingly.

 $ Examples $
   - Get boundaries for a 3-section-array
     \{
           [s, e] = slnums2bounds([3 2 4])

           s = 
                1     4     6
           e =
                3     5     9
     \}

 $ History $
   - Created by Dahua Lin on Nov 20th, 2005

CROSS-REFERENCE INFORMATION

This function calls:

This function is called by:

• sledgeset2adjlist SLEDGESET2ADJLIST Converts edge set to adjacency list
• slpruneedgeset SLPRUNEEDGESET Prunes the edge set
• slgda SLGDA Performs Baudat's Generalized Discriminant Analysis
• sllogistreg SLLOGISTREG Performs Multivariate Logistic Regression
• slcovs SLCOVS Computes the sample covariance matrix
• slmeans SLMEANS Compute the mean vectors
• slposterioritrue SLPOSTERIORITRUE Computes the posteriori that samples belong to true class
• sldlda SLDLDA Performs Direct Linear Discriminant Analysis
• slfld SLFLD Performs Fisher Linear Discriminant Analysis
• slnlda SLNLDA Performs Nullspace-based Linear Discriminant Analysis
• slscatter SLSCATTER Compute the scatter matrix
• sllabelinds SLLABELINDS Extract indices corresponding to specified labels
• sldrawpts SLDRAWPTS Draws a set of sample points on axes

SOURCE CODE

0001 function [spos, epos] = slnums2bounds(nums)
0002 %SLNUMS2BOUNDS Compute the index-boundaries from section sizes
0003 %
0004 % $ Syntax $
0005 %   - [spos, epos] = slnums2bounds(nums)
0006 %   - spos = slnums2bounds(nums)
0007 %
0008 % $ Description $
0009 %   - [spos, epos] = slnums2bounds(nums) obtains the start positions and
0010 %     end positions of the sections given the number of elements in
0011 %     the sections.
0012 %
0013 %   - spos = slnums2bounds(nums) only retrieves the start positions.
0014 %
0015 % $ Reamrks $
0016 %   # nums can be either a row vector or a column vector. then the results
0017 %     will be row vector or column vector correspondingly.
0018 %
0019 % $ Examples $
0020 %   - Get boundaries for a 3-section-array
0021 %     \{
0022 %           [s, e] = slnums2bounds([3 2 4])
0023 %
0024 %           s =
0025 %                1     4     6
0026 %           e =
0027 %                3     5     9
0028 %     \}
0029 %
0030 % $ History $
0031 %   - Created by Dahua Lin on Nov 20th, 2005
0032 %
0033 
0034 %% parse and verify input arguments
0035 [d1, d2] = size(nums);
0036 if d1 == 1          % row vector
0037     iscol = false;
0038 elseif d2 == 1      % column vector
0039     iscol = true;
0040 else
0041     error('sltoolbox:notvector', 'nums should be a row/column vector');
0042 end
0043     
0044 
0045 %% compute
0046 cs = cumsum(nums);
0047 if iscol
0048     spos = [1; cs(1:end-1)+1];
0049 else
0050     spos = [1, cs(1:end-1)+1];
0051 end
0052 if nargout >= 2
0053     epos = cs;
0054 end
0055 
0056     
0057

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