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What does <I>/<sigmaI> and <I/sigmaI> meanFrom $1Table of contentsNo headersThe <> connotes taking the mean of the variable inside it . So "<I>" is the mean "I" or mean Intensity To describe this statistic I will simply a reply to a question on ccp4bb given by Anastassis Perrakis
Hi -
"I Sigma I" means nothing. <I>/<sigma(I)> is the average intensity of a group of reflections divided by the average standard deviation (sigma) of the same group of reflections. Usually its reported per resolution shell, groups of reflections within thin shells of resolution. <I/sigma(I)> is the intensity divided by the standard deviation (sigma) of a reflection, averaged for a group of reflections. Its also usually reported per resolution shell, groups of reflections within thin shells of resolution. Both report signal over noise, and in many (most?) publications its unclear which one is reported. They are similar but not the same. Hope this helps. Other posts in this thread are available at a google search for ccp4bb and "I on sigI"
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