%CAT2DATA Create categorical dataset
%
% A = CAT2DATA(DATA,LABELS)
%
% INPUT
% DATA Cell array or integer array with categorical data
% LABELS Desired labels, default: unlabeled
%
% OUTPUT
% A Dataset
%
% DESCRIPTION
% This routine creates a dataset of categorical data, either given as
% integers, or as a set of string arrays. If given the dataset is labeled
% by LABELS. In case DATA is a cell array of size [1,K], it is assumed that
% every cell contains a string array of M named categories, in which M is
% the number of objects. In case DATA is a cell array of size [M,1], it is
% assumed that every cell contains a string array of K named categories,
% one for every feature. Alternatively DATA can be a [M,K] cell array
% containing a single string per cell.
%
% The routine FEAT2LAB may be used to convert a categorical feature into a
% class label.
%
% A categorical dataset A can be combined with a dataset B representing a
% set of numeric features for the same objects by [A B].
%
% SEE ALSO (<a href="http://37steps.com/prtools">PRTools Guide</a>)
% DATASETS, PRDATASET, SETFEATDOM, GETFEATDOM, FEAT2LAB
% Copyright: R.P.W. Duin, r.p.w.duin@37steps.com
function a = cat2data(data,labels)
if nargin < 2, labels = []; end
if isdouble(data)
[m,k] = size(data)
a = prdataset(data,labels);
featdom = cell(1,k);
for j=1:k
featdom{j} = unique(data(:,j))';
end
elseif ischar(data)
[ndat,lablist]=renumlab(data);
a = prdataset(ndat,labels);
featdom = {lablist};
elseif iscell(data) && size(data,1) == 1
% data is given feature wise: as char arrays over columns
k = numel(data);
m = size(data{1},1);
ndat = zeros(m,k);
featdom = cell(1,k);
for j=1:k
[ndatj,lablistj]=renumlab(data{j});
if size(ndat,1) ~= m
error('Each set of nominal features should be based on the same number of objects')
end
ndat(:,j) = ndatj;
featdom{j} = lablistj;
end
a = prdataset(ndat,labels);
elseif iscell(data) && size(data,2) == 1
% data is given object wise: as char arrays over rows, Let's transpose it
m = numel(data);
k = size(data{1},1);
data2 = cell(m,k);
data1 = cell(1,k);
for i=1:m
data2(i,:) = cellstr(data{i});
end
for j=1:k
data1{j} = char(data2(:,j));
end
a = feval(mfilename,data1,labels);
return
elseif iscell(data)
% data is given as a 2D cell array with a single string per cell
[m,k] = size(data);
data1 = cell(1,k);
for j=1:k
data1{j} = char(data(:,j));
end
a = feval(mfilename,data1,labels);
return
else
error('Data should be given as doubles or as a char cell array')
end
a = setfeatdom(a,featdom);
return