path: root/doc/man/process_hkl.1

.\"
.\" process_hkl man page
.\"
.\" Copyright © 2012-2014 Deutsches Elektronen-Synchrotron DESY,
.\"                       a research centre of the Helmholtz Association.
.\"
.\" Part of CrystFEL - crystallography with a FEL
.\"

.TH PROCESS_HKL 1
.SH NAME
process_hkl \- Monte Carlo merging of Bragg intensities
.SH SYNOPSIS
.PP
.B process_hkl
\fB-i\fR \fImypatterns.stream\fR \fB-o\fR \fImydata.hkl\fR \fB-y\fR \fIpointgroup\fR [\fBoptions\fR] \fB...\fR
.PP
.B process_hkl
\fB--help\fR

.SH DESCRIPTION
process_hkl takes a data stream, such as that from \fBindexamajig\fR, and merges
the many individual intensities together to form a single list of reflection
intensities which are useful for crystallography.  Merging is done by the Monte
Carlo method, otherwise known as taking the mean of the individual values.

.SH OPTIONS
.PD 0
.IP "\fB-i\fR \fIfilename\fR"
.IP \fB--input=\fR\fIfilename\fR
.PD
Give the name of the input stream.  \fB--input=-\fR means to use stdin.

.PD 0
.IP "\fB-o\fR \fIfilename\fR"
.IP \fB--output=\fR\fIfilename\fR
.PD
Give the name of the output file.  The default is \fB--output=processed.hkl\fR.

.PD 0
.IP "\fB-y\fR \fIpointgroup\fR"
.IP \fB--symmetry=\fR\fIpointgroup\fR
.PD
Merge according to symmetry \fIpointgroup\fR.

.PD 0
.IP "\fB-g\fR \fIh,k,l\fR"
.IP \fB--histogram=\fR\fIh,k,l\fR
.PD
Calculate a histogram of intensities for \fIh,k,l\fR, which will be written as
\fBhistogram.dat\fR in the current directory.

.PD 0
.IP "\fB-z\fR \fImin,max,nbins\fR"
.IP \fB--hist-parameters=\fR\fImin,max,nbins\fR
.PD
Set the minimum and maximum values, and the number of bins, to \fImin\fR, \fImax\fR and \fInbins\fR, respectively.

.PD 0
.IP \fB--start-after=\fR\fIn\fR
.PD
Ignore the first \fIn\fR crystals in the input.  The default is \fB--start-after=0\fR, i.e. start at the beginning.

.PD 0
.IP \fB--stop-after=\fR\fIn\fR
.PD
Stop processing after \fIn\fR crystals have been successfully merged.  The default is \fB--stop-after=0\fR, which means to process all the patterns from the start point to the end of the input (see \fB--start-after\fR).

.PD 0
.IP \fB--reference=\fR\fIfilename\fR
.PD
Use intensities from \fIfilename\fR as the reference when scaling, instead of
the current model.

.PD 0
.IP \fB--scale\fR
.PD
Attempt to scale each pattern for best fit with the current model.

Scaling using process_hkl doesn't work very well: use \fBpartialator\fR if you
need more advanced merging techniques.

.PD 0
.IP \fB--no-polarisation\fR
.PD
Disable the polarisation correction.

.PD 0
.IP \fB--min-measurements=\fR\fIn\fR
.PD
Include a reflection in the output only if it appears at least least \fIn\fR times.  The default is \fB--min-measurements=2\fR.

.PD 0
.IP \fB--min-snr=\fR\fIn\fR
.PD
Use a particular individual reflection intensity measurement only if it exceeds its estimated standard error by at least \fIn\fR.  The default is -infinity, i.e. no cutoff.
.IP
\fBWARNING:\fR think very carefully before using this option.  It will bias reflections towards more positive values, even where no signal exists, leading to a data set dominated by the background.  This can invalidate some of the figures of merit for the merit for data quality while severely compromising the actual quality.

.PD 0
.IP \fB--max-adu=\fR\fIn\fR
.PD
Include reflections only if their peak values were less than \fIn\fR.  That means, \fIn\fR is the saturation value of the detector.  The default is infinity, i.e. no cutoff.

.PD 0
.IP \fB--min-res=\fR\fIn\fR
.PD
Merge crystals only if they diffract to beyond \fIn\fR Angstroms resolution.  The default is zero, i.e. no cutoff.  The resolution is taken from the diffraction_resolution_limit line in the stream.

.PD 0
.IP \fB--push-res=\fIn\fR
.PD
Integrate \fIn\fR nm^-1 higher than the apparent resolution limit of each individual crystal.  \fIn\fR can be negative to integrate \fIlower\fR than the apparent resolution limit.  The default is \fB--rescut=inf\fR, which means no resolution cutoff at all.

.SH CHOICE OF POINT GROUP FOR MERGING

One of the main features of serial crystallography is that the orientations of
individual crystals are random.  That means that the orientation of each
crystal must be determined independently, with no information about its
relationship to the orientation of crystals in other patterns.

Some symmetry classes are merohedral, which means that they have lower symmetry than their lattices. This means that the orientation determined by indexing will have an ambiguity.  In such cases, you will need to merge according to corresponding holohedral point group.  To determine what this is, consult the tables in \fRtwin-calculator.pdf\fB.

.SH AUTHOR
This page was written by Thomas White.

.SH REPORTING BUGS
Report bugs to <taw@physics.org>, or visit <http://www.desy.de/~twhite/crystfel>.

.SH COPYRIGHT AND DISCLAIMER
Copyright © 2012-2014 Deutsches Elektronen-Synchrotron DESY, a research centre of the Helmholtz Association.
.P
qprocess_hkl, and this manual, are part of CrystFEL.
.P
CrystFEL is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
.P
CrystFEL is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
.P
You should have received a copy of the GNU General Public License along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.

.SH SEE ALSO
.BR crystfel (7),
.BR indexamajig (5),
.BR compare_hkl (1),
.BR check_hkl (1),
.BR render_hkl (1),
.BR ambigator (1),
.BR partialator (1)