.. algorithm::

.. summary::

.. relatedalgorithms::

.. properties::

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

Calculates and applies corrections for scattering abs absorption in a annular
sample for a run on an indirect inelastic instrument, optionally allowing for
the subtraction or corrections of the container.

The correction factor workspace is a workspace group containing the correction
factors in the Paalman and Pings format, note that only :math:`{A_{s,s}}` and
:math:`A_{c,c}` factors are calculated by this algorithm.

Workflow
--------

.. diagram:: IndirectAnnulusAbsorption-v1_wkflw.dot


Usage
-----

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

**Example - Sample corrections for IRIS:**

.. testcode:: SampleCorrectionsWithCanSubtraction

    red_ws = LoadNexusProcessed(Filename='irs26176_graphite002_red.nxs')
    can_ws = LoadNexusProcessed(Filename='irs26173_graphite002_red.nxs')

    corrected, fact = IndirectAnnulusAbsorption(SampleWorkspace=red_ws,
                                                SampleChemicalFormula='H2-O',
                                                CanWorkspace=can_ws,
                                                CanScaleFactor=0.8,
                                                CanInnerRadius=0.19,
                                                SampleInnerRadius=0.2,
                                                SampleOuterRadius=0.25,
                                                CanOuterRadius=0.26,
                                                Events=200,
                                                Version=1)

    ass = fact[0]

    print ('Corrected workspace is intensity against %s'
          % (corrected.getAxis(0).getUnit().caption()))

    print ('Ass workspace is %s against %s'
          % (ass.YUnitLabel(), ass.getAxis(0).getUnit().caption()))

.. testcleanup:: SampleCorrectionsWithCanSubtraction

   DeleteWorkspace(red_ws)
   DeleteWorkspace(can_ws)
   DeleteWorkspace(corrected)
   DeleteWorkspace(fact)

**Output:**

.. testoutput:: SampleCorrectionsWithCanSubtraction

  Corrected workspace is intensity against Energy transfer
  Ass workspace is Attenuation factor against Wavelength

**Example - Sample corrections for IRIS:**

.. testcode:: SampleAndCanCorrections

    red_ws = LoadNexusProcessed(Filename='irs26176_graphite002_red.nxs')
    can_ws = LoadNexusProcessed(Filename='irs26173_graphite002_red.nxs')

    corrected, fact = IndirectAnnulusAbsorption(SampleWorkspace=red_ws,
                                                SampleChemicalFormula='H2-O',
                                                CanWorkspace=can_ws,
                                                CanChemicalFormula='H2-O',
                                                CanInnerRadius=0.19,
                                                SampleInnerRadius=0.2,
                                                SampleOuterRadius=0.25,
                                                CanOuterRadius=0.26,
                                                Events=200,
                                                UseCanCorrections=True,
                                                Version=1)

    ass = fact[0]
    acc = fact[1]

    print ('Corrected workspace is intensity against %s'
          % (corrected.getAxis(0).getUnit().caption()))

    print ('Ass workspace is %s against %s'
          % (ass.YUnitLabel(), ass.getAxis(0).getUnit().caption()))

    print ('Acc workspace is %s against %s'
          % (acc.YUnitLabel(), acc.getAxis(0).getUnit().caption()))

.. testcleanup:: SampleAndCanCorrections

   DeleteWorkspace(red_ws)
   DeleteWorkspace(can_ws)
   DeleteWorkspace(corrected)
   DeleteWorkspace(fact)

**Output:**

.. testoutput:: SampleAndCanCorrections

  Corrected workspace is intensity against Energy transfer
  Ass workspace is Attenuation factor against Wavelength
  Acc workspace is Attenuation factor against Wavelength

.. categories::

.. sourcelink::