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→Statistics of unique reflections: Rpim calculation
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== Scaling information == | == 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 === | === 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 | |||
1.042E+00 2.177E-04 66.41 | |||
</pre> | |||
== Statistics of reflections == | == Statistics of reflections == | ||
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The file XDS_ASCII.HKL actually has all 531700 reflections. | 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% . | |||