%PRDATASET Load and convert dataset from disk%%  A = PRDATASET(NAME,M,N)%% The dataset given in NAME is loaded from a .mat file and converted% to the current PRTools definition. Objects and features requested% by the index vectors M and N are returned.%% See PRDATA for loading arbitrary data into a PRTools dataset.% See PRDATASETS for an overview of datasets.% Copyright: R.P.W. Duin, duin@ph.tn.tudelft.nl% Faculty of Applied Sciences, Delft University of Technology% P.O. Box 5046, 2600 GA Delft, The Netherlands% $Id: prdataset.m,v 1.2 2006/03/08 22:06:58 duin Exp $function a = prdataset(name,M,N)	prtrace(mfilename);		persistent FIRST;         if isempty(FIRST), FIRST = 1; end	if nargin < 3, N = []; end	if nargin < 2, M = []; end	if exist([name '.mat']) ~= 2		error([newline '---- Dataset ''' name ''' not available ----'])	end	s = warning;	warning off	b = load(name);	warning(s);	% Try to find out what data we actually loaded:	names = fieldnames(b);	eval(['a = b.' names{1} ';']);	if ~isdataset(a) & ndims(a) > 2		% We loaded an image?  		a = im2feat(a);		prwarning(2,'Assumed that a feature image is loaded')	else		a = dataset(a);	end	[m,k] = size(a);	% Maybe a subset of the features is requested:	if ~isempty(N) 		if min(size(N)) ~= 1			error([newline 'Feature indices should be stored in vector'])		end		if max(N) > k			error([newline 'Dataset has not the requested features'])		end		a = a(:,N); 	end	% Maybe a subset of the objects are requested:	if ~isempty(M) 		if min(size(M)) ~= 1			error([newline 'Object indices should be stored in vector'])		end		if max(M) > m			error([newline 'Dataset has not the requested objects'])		end		a = a(M,:); 	end	if FIRST		disp(' ')		disp('*** You are using one of the datasets distibuted by PRTools. Most of them')		disp('*** are publicly available on the Internet and converted to the PRTools')		disp('*** format. See the Contents of the datasets directory (HELP PRDATASETS)')		disp('*** or the load routine of the specific dataset to retrieve its source.')		disp(' ')		FIRST = 0;	end	return