# CORRECT.LP

XDS, like SCALA and d*TREK, gives statistics about unaveraged and averaged quantities, but in different tables. The unaveraged values are in a table that is fine-grained in terms of resolution, at the beginning of CORRECT.LP. The Sigma values in that table are corrected to match the RMS scatter.

The table that has information about the averaged data (suitably weighted) is repeated several times. It is less fine-grained in resolution (9 shells, and overall). [if a user wants this table in fine-grained form, s/he can use XSCALE].

The way the tables are printed is the same for both types of tables: at first the definitions of the quantities in the table are given, and then the table itself is printed.

Specifically, the heading of the table which talks about the unaveraged data looks like this:

I/Sigma = mean intensity/Sigma of a reflection in shell Chi2 = goodness of fit between sample variances of symmetry-related intensities and their errors (Chi2 = 1 for perfect agreement) R-FACTOR observed = (SUM(ABS(I(h,i)-I(h))))/(SUM(I(h,i))) expected = expected R-FACTOR derived from Sigma(I) NUMBER = number of reflections in resolution shell used for calculation of R-FACTOR ACCEPTED = number of accepted reflections REJECTED = number of rejected reflections (MISFITS), recognized by comparison with symmetry-related reflections.

and then the table itself is:

RESOLUTION RANGE I/Sigma Chi2 R-FACTOR R-FACTOR NUMBER ACCEPTED REJECTED observed expected 39.660 19.587 8.23 0.96 6.36 7.12 929 940 75 19.587 14.780 7.39 0.88 5.94 7.46 1956 1959 66 .... (many resolution shells deleted for brevity)

and later it gives the table for the averaged intensities with heading

R-FACTOR observed = (SUM(ABS(I(h,i)-I(h))))/(SUM(I(h,i))) expected = expected R-FACTOR derived from Sigma(I) COMPARED = number of reflections used for calculating R-FACTOR I/SIGMA = mean of intensity/Sigma(I) of unique reflections (after merging symmetry-related observations) Sigma(I) = standard deviation of reflection intensity I estimated from sample statistics R-meas = redundancy independent R-factor (intensities) Rmrgd-F = quality of amplitudes (F) of this data set For definition of R-meas and Rmrgd-F see Diederichs & Karplus (1997), Nature Struct. Biol. 4, 269-275. (rest of heading deleted for brevity)

and the table itself is

SUBSET OF INTENSITY DATA WITH SIGNAL/NOISE >= -3.0 AS FUNCTION OF RESOLUTION RESOLUTION NUMBER OF REFLECTIONS COMPLETENESS R-FACTOR R-FACTOR COMPARED I/SIGMA R-meas Rmrgd-F Anomal SigAno LIMIT OBSERVED UNIQUE POSSIBLE OF DATA observed expected Corr 6.66 12698 5958 10069 59.2% 5.3% 6.7% 11577 10.55 6.8% 5.5% -27% 0.740 527 4.74 22569 11140 17519 63.6% 7.3% 7.8% 19592 8.24 9.5% 9.1% -25% 0.734 629 3.88 28199 14683 22445 65.4% 7.9% 7.7% 23437 7.88 10.3% 10.6% -31% 0.769 449 3.37 34407 17986 26530 67.8% 12.3% 12.0% 28131 5.25 16.1% 20.6% -19% 0.777 351 3.01 39636 20921 29958 69.8% 22.7% 23.3% 31896 3.08 29.8% 42.6% -12% 0.644 211 (rest deleted for brevity)

So, the program indicates quite clearly what the statistics refer to.