ViewBOA-v1.rst

.. algorithm::

.. summary::

.. alias::

.. properties::

Description
-----------

The algorithm loads a BOA file using :ref:`algm-LoadSINQ`. It produces three output workspaces, histogram *N*, ysum *N* and psdsum *N*, where *N* is the numor supplied to ViewBOA.

histogram *N* contains the wavelength spectrum and can be plotted using "Plot spectrum...". The other two workspaces can be inspected with the spectrum slice viewer. psdsum *N* shows a beam profile on the two-dimensional detector, whereas ysum *N* shows the distribution of events with TOF on the x-axis and the detector x-coordinate on the y-axis, as indicated in the three images below (histogram, psdsum and ysum from left to right).

.. image:: /images/ViewBOA_output_histogram61.png
   :width: 30%
   :alt: Wavelength spectrum.
      
.. image:: /images/ViewBOA_output_psdsum61.png
   :width: 30%
   :alt: Beam profile.
      
.. image:: /images/ViewBOA_output_ysum61.png
   :width: 30%
   :alt: Neutron TOF distribution along x-direction of detector.
   
Usage
-----

.. include:: ../usagedata-note.txt

The following code loads a BOA file and prints out information about the wavelength distribution of the neutrons.

.. testcode:: ViewBOAEx
    
    import numpy as np

    ViewBOA(2014, 61, 6)
    
    lamdba_distribution = mtd['histogram61'].readY(0)
    lambda_values = mtd['histogram61'].readX(0)
    
    print "The wavelength spectrum is described by", len(lamdba_distribution),"points."
    print "The range covered is", round(lambda_values[0], 4), "-", round(lambda_values[-1], 4), "Angstrom."
    print "The maximum is located at", round(lambda_values[np.argmax(lamdba_distribution)], 4), "Angstrom."
    
This script leads to the following output:
    
.. testoutput:: ViewBOAEx

    The wavelength spectrum is described by 400 points.
    The range covered is 0.7912 - 8.6638 Angstrom.
    The maximum is located at 2.3894 Angstrom.
    
In addition, the three workspaces described above are available, plotting them should produce figures like the above.

.. categories::

.. sourcelink::