Mercurial > hg > ltpda
view m-toolbox/classes/+utils/@math/ecdf.m @ 35:4be5f7a5316f database-connection-manager
Suppress output messages on preferences loading and saving
author | Daniele Nicolodi <nicolodi@science.unitn.it> |
---|---|
date | Mon, 05 Dec 2011 16:20:06 +0100 |
parents | f0afece42f48 |
children |
line wrap: on
line source
% ECDF Compute empirical cumulative distribution function %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Compute empirical cumulative distribution function for a series of data % % CALL % % [F,X] = ecdf(Y); % % INPUT % % - Y, a data series % % L Ferraioli 09-03-2011 % % $Id: ecdf.m,v 1.2 2011/03/09 11:40:27 luigi Exp $ %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% function [F,X] = ecdf(Y) % sort input data X = sort(Y); % define variable for cumulative sum sw = ones(size(X)); n = numel(sw); jj = 2; idd = false(size(sw)); % Fi is calculated practically as Fi = ni/n where ni is the position of % the ith element of the sorted input array. If two or more elements are % equal then only the ni corresponding to the last one is considered and % the other elements are removed. ni is obtained by a cumulative sum of % an arrays of ones. If k elements are equal they are removed and % substituted by a single k. while jj < n+1 if X(jj) ~= X(jj-1); % if successive elements are different we can go on jj = jj+1; else % if some elements are equal than we have to count the equal elements jt = jj+1; while jt<=n+1 && X(jt-1)==X(jj-1) % counting equal elements jt = jt + 1; end for ji=jj:jt-2 idd(ji-1) = true; % make the assignement for successive removal of elements end t = jt-jj; % set the value corresponding to the number of equal elements in % correspondence to the last element of the series of eqials sw(jt-2) = t; jj = jt; end end % remove unwanted elements corresponding to duplicates sw(idd) = []; % calculate cumulative distribution by cumulative sum F = cumsum(sw)./n; % remove elements corresponding to replicas X(idd) = []; end