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→‎Statistics of unique reflections: Rpim calculation

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 == Scaling information ==
+<pre>
+ ******************************************************************************
+           CORRECTION FACTORS AS FUNCTION OF IMAGE NUMBER & RESOLUTION
+ ******************************************************************************
+ RECIPROCAL CORRECTION FACTORS FOR INPUT DATA SETS MERGED TO
+ OUTPUT FILE: XDS_ASCII.HKL
+ THE CALCULATIONS ASSUME         FRIEDEL'S_LAW= TRUE
+ TOTAL NUMBER OF CORRECTION FACTORS DEFINED       40
+ DEGREES OF FREEDOM OF CHI^2 FIT              2649.6
+ CHI^2-VALUE OF FIT OF CORRECTION FACTORS      1.557
+ NUMBER OF CYCLES CARRIED OUT                      3
+ CORRECTION FACTORS for visual inspection by XDS-Viewer DECAY.cbf
+ XMIN=     0.2 XMAX=    99.7 NXBIN=    2
+ YMIN= 0.00100 YMAX= 0.50246 NYBIN=   20
+ NUMBER OF REFLECTIONS USED FOR DETERMINING CORRECTION FACTORS       4832
+ ******************************************************************************
+  CORRECTION FACTORS AS FUNCTION OF X (fast) & Y(slow) IN THE DETECTOR PLANE
+ ******************************************************************************
+ RECIPROCAL CORRECTION FACTORS FOR INPUT DATA SETS MERGED TO
+ OUTPUT FILE: XDS_ASCII.HKL
+ THE CALCULATIONS ASSUME         FRIEDEL'S_LAW= TRUE
+ TOTAL NUMBER OF CORRECTION FACTORS DEFINED       90
+ DEGREES OF FREEDOM OF CHI^2 FIT              2640.3
+ CHI^2-VALUE OF FIT OF CORRECTION FACTORS      1.456
+ NUMBER OF CYCLES CARRIED OUT                      4
+ CORRECTION FACTORS for visual inspection by XDS-Viewer MODPIX.cbf
+ XMIN=   232.6 XMAX=  3623.4 NXBIN=    9
+ YMIN=   313.3 YMAX=  4064.2 NYBIN=   10
+ NUMBER OF REFLECTIONS USED FOR DETERMINING CORRECTION FACTORS       4832
+ ******************************************************************************
+   CORRECTION FACTORS AS FUNCTION OF IMAGE NUMBER & DETECTOR SURFACE POSITION
+ ******************************************************************************
+ RECIPROCAL CORRECTION FACTORS FOR INPUT DATA SETS MERGED TO
+ OUTPUT FILE: XDS_ASCII.HKL
+ THE CALCULATIONS ASSUME         FRIEDEL'S_LAW= TRUE
+ TOTAL NUMBER OF CORRECTION FACTORS DEFINED       26
+ DEGREES OF FREEDOM OF CHI^2 FIT              2652.0
+ CHI^2-VALUE OF FIT OF CORRECTION FACTORS      1.418
+ NUMBER OF CYCLES CARRIED OUT                      3
+ CORRECTION FACTORS for visual inspection by XDS-Viewer ABSORP.cbf
+ XMIN=     0.2 XMAX=    99.7 NXBIN=    2
+ DETECTOR_SURFACE_POSITION=    1928    2189
+ DETECTOR_SURFACE_POSITION=    2504    2826
+ DETECTOR_SURFACE_POSITION=    1352    2826
+ DETECTOR_SURFACE_POSITION=    1352    1552
+ DETECTOR_SURFACE_POSITION=    2504    1552
+ DETECTOR_SURFACE_POSITION=    3231    2786
+ DETECTOR_SURFACE_POSITION=    2468    3630
+ DETECTOR_SURFACE_POSITION=    1388    3630
+ DETECTOR_SURFACE_POSITION=     625    2786
+ DETECTOR_SURFACE_POSITION=     625    1592
+ DETECTOR_SURFACE_POSITION=    1388     747
+ DETECTOR_SURFACE_POSITION=    2468     747
+ DETECTOR_SURFACE_POSITION=    3231    1592
+ NUMBER OF REFLECTIONS USED FOR DETERMINING CORRECTION FACTORS       4832
+</pre>
 === Details about the error model ===
+<pre>
+******************************************************************************
+    CORRECTION PARAMETERS FOR THE STANDARD ERROR OF REFLECTION INTENSITIES
+ ******************************************************************************
+ The variance v0(I) of the intensity I obtained from counting statistics is
+ replaced by v(I)=a*(v0(I)+b*I^2). The model parameters a, b are chosen to
+ minimize the discrepancies between v(I) and the variance estimated from
+ sample statistics of symmetry related reflections. This model implicates
+ an asymptotic limit ISa=1/SQRT(a*b) for the highest I/Sigma(I) that the
+ experimental setup can produce (Diederichs (2010) Acta Cryst D66, 733-740).
+     a        b          ISa
+.042E+00  2.177E-04   66.41
+</pre>
 == Statistics of reflections ==
@@ Line 226: / Line 311: @@
 The file XDS_ASCII.HKL actually has all 531700 reflections.
+=== Notes ===
+How to calculate Rpim from the numbers in the table: take the Rmeas value and divide by the square root of the multiplicity. The multiplicity is the number of observations divided by the number of unique reflections. Example: the table above shows Rmeas of 33.5% overall, observed 515976 overall, with 173389 uniques. Thus Rpim = 33.5% / SQRT(515976/173389) = 19.4% .