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(New page: A useful Unix command for evaluating the overall quality of an experimental setup is awk '/CORRECTION PARAMETERS/{for (i=0;i<9;++i) getline;print 1/($1*$2)^0.5}' CORRECT.LP Why? Because t...)
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Revision as of 12:57, 22 November 2009

A useful Unix command for evaluating the overall quality of an experimental setup is

awk '/CORRECTION PARAMETERS/{for (i=0;i<9;++i) getline;print 1/($1*$2)^0.5}' CORRECT.LP

Why? Because this will give you the maximum value of I/sigma(I) for any reflection in your dataset, no matter how good your crystal is.

Why does the command give you such a useful value? It just finds the line "CORRECTION PARAMETERS FOR THE STANDARD ERROR OF REFLECTION INTENSITIES", goes 9 lines down, and grabs the values of a and b from CORRECT.LP . These values appear in the formula v(I)=a*(v0(I)+b*I^2) which is used to adjust the squares of the sigmas to match their experimental spread.