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Xscale: Difference between revisions
→for individual reflections: explain 0-dose a bit more
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CRYSTAL_NAME=Pt | CRYSTAL_NAME=Pt | ||
'''A word of warning''': even if the internal quality indicators (R-factors) are better when using this feature, there is no guarantee that the resulting intensities will actually be better suited for your purposes than those obtained without it. In particular, extrapolating to the ends of the dose interval (0 dose and full dose) decreases the precision of the intensities. The optimal points for interpolation are near 1/4 and near 3/4 of the total dose. Details are published in [http://dx.doi.org/10.1107/S0021889808036716 Diederichs, K., Junk, M. (2009) Post-processing intensity measurements at favourable dose values. ''J. Appl. Cryst.'' '''42''', 48-57]. | '''A word of warning''': even if the internal quality indicators (R-factors) are better when using this feature, there is no guarantee that the resulting intensities will actually be better suited for your purposes than those obtained without it. In particular, extrapolating to the ends of the dose interval (0 dose and full dose) decreases the precision of the intensities. | ||
The optimal points for interpolation are near 1/4 and near 3/4 of the total dose. Details are published in [http://dx.doi.org/10.1107/S0021889808036716 Diederichs, K., Junk, M. (2009) Post-processing intensity measurements at favourable dose values. ''J. Appl. Cryst.'' '''42''', 48-57]. | |||
To interpolate to 22% of the full dose, one has to give a STARTING_DOSE less than zero: | |||
OUTPUT_FILE=hg.ahkl | |||
INPUT_FILE= ../xds-hg/XDS_ASCII.HKL ! a mercury soak | |||
CRYSTAL_NAME=Hg | |||
STARTING_DOSE=-22.* ! assuming the dataset has 100 frames | |||
Explanation: the interpolation is done towards 0, and by defining the start of the dataset to be at -22., one tells the program to calculate (by interpolation) those intensity values that would be obtained at dose 0 which in reality is near frame 22. | |||
Another example: by defining STARTING_DOSE=-78.* one would tell the program to calculate, by interpolation, those intensity values that correspond to those that would be obtained near frame 78. | |||
== A hint for long-time XSCALE users == | == A hint for long-time XSCALE users == | ||