--- /dev/null
+function r = rankcorr(X,Y)
+% RANKCORR calculated the rank correlation coefficient.
+% This function is replaced by CORRCOEF.
+% Significance test and confidence intervals can be obtained from CORRCOEF, too.
+%
+% R = CORRCOEF(X, [Y, ] 'Rank');
+%
+% The rank correlation r = corrcoef(ranks(x)).
+% is often confused with Spearman's rank correlation.
+% Spearman's correlation is defined as
+% r(x,y) = 1-6*sum((ranks(x)-ranks(y)).^2)/(N*(N*N-1))
+% The results are different. Here, the former version is implemented.
+%
+% see also: CORRCOEF, SPEARMAN, RANKS
+%
+% REFERENCES:
+% [1] http://mathworld.wolfram.com/SpearmanRankCorrelationCoefficient.html
+% [2] http://mathworld.wolfram.com/CorrelationCoefficient.html
+
+% $Id: rankcorr.m 8223 2011-04-20 09:16:06Z schloegl $
+% Copyright (C) 2000-2003 by Alois Schloegl <alois.schloegl@gmail.com>
+% This function is part of the NaN-toolbox
+% http://pub.ist.ac.at/~schloegl/matlab/NaN/
+
+% This program is free software; you can redistribute it and/or modify
+% it under the terms of the GNU General Public License as published by
+% the Free Software Foundation; either version 2 of the License, or
+% (at your option) any later version.
+%
+% This program 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 General Public License for more details.
+%
+% You should have received a copy of the GNU General Public License
+% along with this program; If not, see <http://www.gnu.org/licenses/>.
+
+
+% warning('RANKCORR might become obsolete; use CORRCOEF(ranks(x)) or CORRCOEF(...,''Rank'') instead');
+
+if nargin < 2
+ r = corrcoef(ranks(X));
+else
+ r = corrcoef(ranks(X),ranks(Y));
+end
\ No newline at end of file