--- /dev/null
+function y = tinv(x,n)
+% TINV returns inverse cumulative function of the student distribution
+%
+% x = tinv(p,v);
+%
+% Computes the quantile (inverse of the CDF) of a the student
+% cumulative distribution with mean m and standard deviation s
+% p,v must be matrices of same size, or any one can be a scalar.
+%
+% see also: TPDF, TCDF, NORMPDF, NORMCDF, NORMINV
+
+% Reference(s):
+
+% $Id: tinv.m 9033 2011-11-08 20:58:07Z schloegl $
+% Copyright (C) 2000-2003,2009 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/>.
+
+
+% allocate output memory and check size of arguments
+if all(size(x)==1)
+ x = repmat(x,size(n));
+elseif all(size(n)==1)
+ n = repmat(n,size(x));
+elseif all(size(x)==size(n))
+ ; %% OK, do nothing
+else
+ error('size of input arguments must be equal or scalar')
+end;
+
+y = norminv(x); % do special cases, like x<=0, x>=1, isnan(x), n > 10000;
+y(~(n>0)) = NaN;
+
+ix = find(~isnan(x) & (n>0) & (n<10000));
+if ~isempty(ix)
+ y(ix) = (sign(x(ix) - 1/2).*sqrt(n(ix)./betainv(2*min(x(ix), 1-x(ix)), n(ix)/2, 1/2) - n(ix)));
+end;
+
+y = reshape(y,size(x));
+
+%!assert(tinv(NaN,4),NaN)