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.. algorithm::
.. summary::
.. alias::
.. properties::
Description
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Here are examples of input and output from PG3 and SNAP:
.. figure:: /images/PG3_Calibrate.png
.. figure:: /images/SNAP_Calibrate.png
The purpose of this algorithm is to calibrate the detector pixels and
write a calibration file. The calibration file name contains the
instrument, run number, and date of calibration. A binary Dspacemap file
that converts from TOF to d-space including the calculated offsets is
also an output option. For ``CrossCorrelation`` option: If one peak is not
in the spectra of all the detectors, you can specify the first n
detectors to be calibrated with one peak and the next n detectors to be
calibrated with the second peak. If a color fill plot of the calibrated
workspace does not look good, do a color fill plot of the workspace that
ends in cc (cross correlation) to see if the ``CrossCorrelationPoints``
and/or ``PeakHalfWidth`` should be increased or decreased. Also plot the
reference spectra from the cc workspace.
Features to improve performance of peak finding
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Define peak fit-window
There are two exclusive approaches to define peak's fit-window.
- ``PeakWindowMax`` All peaks will use this value to define their fitting
- ``FitwindowTableWorkspace`` This is a table workspace by which each peak
will have its individual fit window defined.
Define accepted range of peak's width
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Optional input property ``DetectorResolutionWorkspace`` is a matrix
workspace containing the detector resolution :math:`\Delta(d)/d` for
each spectrum. Combining with property ``AllowedResRange``, it defines the
lower and upper limit for accepted fitted peak width.
Let :math:`c_l = AllowedResRange[0]`, :math:`c_h = AllowedResRange[1]`
and :math:`fwhm` as the peak's fitted width. Then,
.. math:: c_l\times\frac{\Delta(d)}{d} < fwhm < c_h\times\frac{\Delta(d)}{d}
.. seealso :: Algorithm :ref:`algm-EstimateResolutionDiffraction`
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