Integration tool: diff_map
==========================

Purpose
-------

GUI interface for reduction of diffraction tomography
experiments

Diffraction mapping is an imaging experiment where 2D diffraction patterns are
recorded while performing a 2D scan along two axes, one slower and the other fastest.

Diff_map provides a Graphical User Interface (based on top of PyQt, pyFAI and h5py)
which allows the reduction of this 4D dataset into a 3D dataset containing the
two dimension of movement and the many diffraction angles (the output can be q-space for PDF-CT).

.. figure:: ../img/diffmap_main.png
   :align: center
   :alt: image

On the left-hand side, the user can select a bunch of files to be processed.
For now, any image format supported by FabIO is possible, including multi-frame
images, but not ye NeXus files (work ongoing).

On the right-hand side, the motor range can be specified togeather with their
names. The diffraction parameters can be setup in a similar way to *pyFAI-integrate*.
The output name can also be specified.

.. figure:: ../img/diffmap_integrate.png
   :align: center
   :alt: image

The processing is launched using the *Run* button which opens a matplotlib figure
to display the plot of the diffraction pattern and of the map image under
construction.
During this processing, one can select a scatering range to highlight the regions
of interest.

.. figure:: ../img/diffmap_running.png
   :align: center
   :alt: image

Further analysis can be performed on the resulting dataset using the PyMca roitool
where the 1d dataset has to be selected as last dimension.
The result file aims at NeXus compliance.

This tool can be used for tomography experiments if one considers the slow scan
direction as the rotation.

The user interface can be disabled to allow scripting interface and providing a
JSON configuration file (or all the options).

Usage:
------

diff_map [options] imagefiles*

positional arguments:
  FILE                  List of files to integrate. Mandatory without GUI

optional arguments:

**-h**, **--help**
   show this help message and exit

**-V**, **--version**
   show program's version number and exit

**-o** FILE, **--output** FILE
   HDF5 File where processed map will be saved. Mandatory without GUI

**-v**, **--verbose**
   switch to verbose/debug mode, default: quiet

**-P** FILE, **--prefix** FILE
   Prefix or common base for all files

**-e** EXTENSION, **--extension** EXTENSION
   Process all files with this extension

**-t** FAST, **--fast** FAST
   number of points for the fast motion. Mandatory without GUI

**-r** SLOW, **--slow** SLOW
   number of points for slow motion. Mandatory without GUI

**-c** NPT_RAD, **--npt** NPT_RAD
   number of points in diffraction powder pattern. Mandatory without GUI

**-d** FILE, **--dark** FILE
   list of dark images to average and subtract (comma separated list)

**-f** FILE, **--flat** FILE
   list of flat images to average and divide (comma separated list)

**-m** FILE, **--mask** FILE
   file containing the mask, no mask by default

**-p** FILE, **--poni** FILE
   file containing the diffraction parameter (poni-file), Mandatory
   without GUI

**-O** OFFSET, **--offset** OFFSET
   do not process the first files

**-g**, **--gpu**
   process using OpenCL on GPU

**-S**, **--stats**
   show statistics at the end

**--gui**
   Use the Graphical User Interface

**--no-gui**
   Do not use the Graphical User Interface

**--config** CONFIG
   provide a JSON configuration file

Bugs:
.....

Bugs: Many, see hereafter: 1)If the number of files is too large, use
double quotes "\*.edf" 2)There is a known bug on Debian7 where importing
a large number of file can take much longer than the integration itself:
consider passing files in the command line
