%PRMEMORY Set/get size of memory usage
%
% N = PRMEMORY(N)
%
% N : The desired / retrieved maximum size data of matrices (in
% matrix elements)
%
% DESCRIPTION
% This retoutine sets or retrieves a global variable GLOBALPRMEMORY that
% controls the maximum size of data matrices in PRTools. Routines like
% KNNC, KNN_MAP, PARZEN_MAP and TESTP make use of it by computing
% additional loops and avoiding to define very large distance matrices.
% The default for this maximum size is set to 10000000. For most
% computers there is no need to reduce it. There is not much speed up
% to be expected if it is enlarged.
%
% PRMEMORY gives also the number of elements for which a conversion from
% datafiles to datasets is approved.
%
% This facility is illustrated by the following example, using the
% routine PRMEM.
%
% Assume that an array of the size [M x K] has to be computed. The
% numbers of LOOPS and ROWS are determined which are needed such that
% ROWS*K < GLOBALPRMEMORY (a global variable that is initialized in this
% routine, if necessary). The final number of rows for the last loop
% is returned in LAST.
%
% EXAMPLES
% [M,K] = size(A);
% [LOOPS,ROWS,LAST] = prmem(M,K);
% if (LOOPS == 1)
% RESULT = < compute the result based on A >
% else
% RESULT = 0;
% for J =1:LOOPS
% if (J == LOOPS), N = LAST; else N = ROWS; end
% NN = (J-1)*ROWS;
% RESULT = RESULT + < compute a partial result based on A(NN+1:NN+N,:) >
% end
% end
% Copyright: R.P.W. Duin, r.p.w.duin@37steps.com
% Faculty EWI, Delft University of Technology
% P.O. Box 5031, 2600 GA Delft, The Netherlands
% $Id: prmemory.m,v 1.2 2007/04/13 09:30:54 duin Exp $
function n_out = prmemory(n_in)
persistent GLOBALPRMEMORY;
if (isempty(GLOBALPRMEMORY))
GLOBALPRMEMORY = 50000000;
end
if nargin > 0
if ischar(n_in)
n_in = str2num(n_in);
end
GLOBALPRMEMORY = n_in;
end
if nargout > 0
n_out = GLOBALPRMEMORY;
elseif nargin == 0
disp(GLOBALPRMEMORY)
end
return;