53 lines
1.3 KiB
Matlab
53 lines
1.3 KiB
Matlab
% Compute the pdf, cdf and rank distributions for a sequence of numbers.
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%
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% INPUTS: sequence of values: x, (1xn), 'plt' - 'on' or 'off'
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% bin - bin size, default is [], then it gets selected
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% automatically
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% OUTPUTS: pdf, cdf and rank distribution values, plot is optional
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%
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% Note: pdf = frequency distribution, cdf = cumulative frequency,
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% rank = log-log scale of the sorted sequence
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% GB: last updated, November 24 2012
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function [xpdf,ypdf,xcdf,ycdf,logk,logx]=pdfCdfRank(x,plt='off',bin=[])
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xx=unique(x);
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if length(bin)==0; bin = length(xx)/5; end
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for ii=1:numel(xx)
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xcdf(ii) = xx(ii);
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ycdf(ii) = length(find(x<=xx(ii)))/numel(x);
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% how many x's fall in the interval [xx(ii)-0.5*numel(xx)/bin,xx(ii)+0.5*numel(xx)/bin]
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xpdf(ii) = xx(ii);
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ypdf(ii) = length(find(abs(xx(ii)-x)<=0.5*numel(xx)/bin))/numel(x);
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end
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x=-sort(-x);
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logk=log(1:length(x));
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logx=log(x);
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if strcmp(plt,'on')
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set(gcf,'color',[1,1,1])
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subplot(2,2,1)
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hist(x,bin,'facecolor',[0.5 0.5 0.5])
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title('histogram')
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subplot(2,2,3)
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plot(xpdf,ypdf,'k.')
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title('pdf')
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axis('tight')
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subplot(2,2,2)
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plot(xcdf,ycdf,'k.')
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title('cdf')
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axis('tight')
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subplot(2,2,4)
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plot(logk,logx,'k.')
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title('rank')
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axis('tight')
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end |