adddatafield.m.svn-base

a function inside machine learning

function d = addDataField(d, name, value, type, valueName) 
%Add a field to a d struct 
%This copies data and so needs extra memory, unless you specify valueName,
%in which case the old value dissapears! 

% Copyright (C) 2006 Charanpal Dhanjal 

% This library is free software; you can redistribute it and/or
% modify it under the terms of the GNU Lesser General Public
% License as published by the Free Software Foundation; either
% version 2.1 of the License, or (at your option) any later version.
% 
% This library is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
% Lesser General Public License for more details.
% 
% You should have received a copy of the GNU Lesser General Public
% License along with this library; if not, write to the Free Software
% Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
% USA

if (nargin < 4)
    fprintf('%s\n', help(sprintf('%s', mfilename)));
    error('Incorrect number of inputs - see above usage instructions.');
elseif nargin == 4 
    valueName = ''; 
end

if ~strcmp(type, 'examples') & ~strcmp(type, 'labels')  & ~strcmp(type, 'kernel') &  ~strcmp(type, 'indices')
    error('Invalid data field type') 
end 
    
numExamples = size(value, 1); 
numCols = size(value, 2); 

if d.numExamples~= 0 & size(value, 1) ~= d.numExamples 
    error('Added field does not contain correct number of examples'); 
end 

if isfield(d.exampleIndices, name)
    error('Field %s already exists', name); 
end 

if d.numExamples == 0 
    d.numExamples = size(value, 1); 
end 

global dataValues; 
global dataValuesRefCount; 
global dataValuesSlots; 

if isempty(dataValues) & isempty(dataValuesRefCount) & isempty(dataValuesSlots)
    dataValues = cell(1, 1); 
    dataValuesRefCount = 1; 
    dataValuesSlots = 0; 
end 

nextIndex = min(find(dataValuesSlots == 0));

%Bit of a messy way to save memory, but will do 
if strcmp(valueName, ''); 
    dataValues{nextIndex, 1} = value; 
else
    try
        evalin('caller', [sprintf('global dataValues; dataValues{%d, 1} = ', nextIndex) , valueName,  '; clear ', valueName]);
    catch
        lerror = lasterror; 
        error('Variable Rename Failed: %s.', lerror.message)
    end
end

dataValuesRefCount(nextIndex, 1) = 1; 
dataValuesSlots(nextIndex, 1) = 1;

d.globalIndices.(name) = nextIndex; 
d.colIndices.(name) = (1:numCols)'; 
d.exampleIndices.(name) = (1:d.numExamples)'; %Internal indexing 
d.types.(name) = type;

%Add an item to the slots if not there
if sum(dataValuesSlots == 0) == 0 
    dataValuesSlots = [dataValuesSlots; 0];
end