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Re: Statistics of a histogram
From: |
Carlo de Falco |
Subject: |
Re: Statistics of a histogram |
Date: |
Fri, 30 Jan 2009 18:57:51 +0000 |
On 30 Jan 2009, at 18:44, Shaun Jackman wrote:
Hi,
I have a matrix representing samples of data [x n] meaning that x(i)
was observed n(i) times. Are there functions to calculate the
statistics of observations in this format? I can calculate the mean
easily enough:
sum(x .* n) / sum(n)
How do find the pth percentile?
assuming
a = [ x1,n1; x2,n2; ... ];
I beleive you could do something like:
nn = cumsum(a(:,2));
nn /= nn(end);
xp = max( a(nn<p/100,1) )
but I'm sure there is some octave-forge function to do this, have you
looked at the statistics package?
Cheers,
Shaun
c.