Mercurial Hosting > traffic-intelligence
changeset 301:27f06d28036d
added simple helper for confidence intervals
author | Nicolas Saunier <nicolas.saunier@polymtl.ca> |
---|---|
date | Mon, 11 Mar 2013 01:07:08 -0400 |
parents | f65b828e5521 |
children | 9d88a4d97473 |
files | python/utils.py |
diffstat | 1 files changed, 9 insertions(+), 0 deletions(-) [+] |
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--- a/python/utils.py Wed Feb 13 18:26:49 2013 -0500 +++ b/python/utils.py Mon Mar 11 01:07:08 2013 -0400 @@ -58,6 +58,15 @@ # simple statistics ######################### +def confidenceInterval(mean, stdev, nSamples, percentConfidence, printLatex = False): + from math import sqrt + from scipy.stats.distributions import norm + k = round(norm.ppf(0.5+percentConfidence/200., 0, 1)*100)/100. # 1.-(100-percentConfidence)/200. + e = k*stdev/sqrt(nSamples) + if printLatex: + print('${0} \pm {1}\\frac{{{2}}}{{\sqrt{{{3}}}}}$'.format(mean, k, stdev, nSamples)) + return mean-e, mean+e + def computeChi2(expected, observed): '''Returns the Chi2 statistics''' result = 0.