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Man page of XGEN
XGEN
Section: XGEN Commands (1)
Updated: April 2005
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NAME
XGEN  strategy
SYNOPSIS
strategy
[a] [yval] [resmin] [resmax]
DESCRIPTION
strategy examines the sample and detector parameters contained in a UPARAMS
file and uses them to calculate and plot an appropriate data acquisition
strategy. Currently the program works only for simple geometries, i.e.
either an omega rotation or a phi rotation with chi or kappa equal to zero.
The output is a matrix showing the range of phi required to achieve various
levels of data completeness for each starting value of phi. Thus if it
determines that 99% completeness can be obtained for a start value of phi
equal to 68 degrees only if we cover 120 degrees (68188), then the matrix
element in the phi=68 row and the 99% completeness column will be 120. By
default it examines phi values on a 4 degree granularity (0, 4, 8, ...) and
reports on the deltaphi required for completeness levels of 0.50, 0.75, 0.90,
0.94, 0.99, 0.995, 0.999, and 1.0000. For each level of completeness it reports
relative to both achievable reflections and total reflections; thus if we can
only achieve 98.1% completeness (a typical value, given Lorentz exclusions),
then the top of the table will look like
Symmetrytransformed reflections under scrutiny:
 predictable unobtainable

total
 95484

1801 97285

Summary of strategy calculation

 Deltaphi required for the fractional completeness of:

Start phi  0.5000 0.7500 0.9000 0.9400 0.9700 0.9900 0.9950 0.9990 1.0000

 0.4907 0.7361 0.8833 0.9226 0.9520 0.9717 0.9766 0.9805 0.9815
 0.00 

24.00 36.00 68.00 96.00 132.00 196.00 228.00 332.00 360.00
 4.00 

20.00 36.00 68.00 100.00 136.00 196.00 224.00 332.00 360.00
where the top row of completeness values (0.5000, 0.7500, . . . ) correspond
to the fraction of achievable reflections, whereas the next row
(0.4907, 0.7361, 0.8833 ...) corresponds to the fraction of total reflections.
The output of "strategy" is written to the log file and to a file called
strategy.out in the current directory. The strategy.out version is designed
to be compatible with BLTbased or WxPythonbased plotting packages.

a If specified, strategy will treat a reflection as

 unobtainable _only_ if its Lorentz correction is truly zero.
Otherwise reflections will be treated as unobtainable if their
Lorentz correction is smaller than a cutoff, by default 0.03.
 y<val>

If specified, the Lorentz correction cutoff (see above)
is set to the value <val>.
 <resmax>

This specifies a highresolution cutoff, such that
reflections at higher resolution than this cutoff
(smaller D spacing) will not be predicted. Setting this
parameter to a more restrictive value than the edge of
the detector will make the program run faster.
 <resmin>

This specifies the lowresolution cutoff
below which reflections will not be predicted.
EXAMPLES
 strategy y0.01 50 1.8

Perform a strategy calculation with the

Lorentz correction cutoff set to 0.01 over a resolution
range of 50 to 1.8 Angstroms:
REPORTING BUGS
Report bugs to Andy Howard at howard@iit.edu or 3125675881.
COPYRIGHT
Copyright © 2002, Illinois Institute of Technology.
See the file 'LICENSE' for information on usage and redistribution
of this file, and for a DISCLAIMER OF ALL WARRANTIES
Index
 NAME

 SYNOPSIS

 DESCRIPTION

 Symmetrytransformed reflections under scrutiny:

 EXAMPLES

 REPORTING BUGS

 COPYRIGHT

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Time: 02:08:09 GMT, October 03, 2005