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function se=std_err(sig,varargin) % % Standard error for mean, proportion and estimates. % Options are: % % For standard error of mean: % % se=std_err(sig,n,'mean') % % Where sig is standard deviation estimate, n number of samples. % % For standard error of proportion % % se=std_err(p,n,'proportion') % % Wher p is the percent of the proportion. % % For standard error of estimates: % % se=std_err(sig,n,'estimates',r) % % Where r is the correlation between the predictor and the estimate. % _______________________________________________________________________________ % Copyleft (l) 2010 by Ikaro Silva, All Rights Reserved % Contact Ikaro Silva (ikarosilva@ieee.org) % % This library (Biosignal Toolbox) 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, write to the Free Software % Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA % 02111-1307 USA % % _______________________________________________________________________________ % n=varargin(1); switch varargin(2) case 'mean' se=sig/sqrt(n); case 'proportion' se=sqrt( (sig*(1-sig))/n ); case 'estimate' r=varargin(3); se=sig*( (1-r^2)*( (n-1)/(n-2) ) )^0.5; end