SofQWPolygon v1

../_images/SofQWPolygon-v1_dlg.png

SofQWPolygon dialog.

Summary

Calculate the intensity as a function of momentum transfer and energy.

Alias

This algorithm is also known as: SofQW2

Properties

Name Direction Type Default Description
InputWorkspace Input MatrixWorkspace Mandatory Reduced data in units of energy transfer DeltaE. The workspace must contain histogram data and have common bins across all spectra.
OutputWorkspace Output MatrixWorkspace Mandatory The name to use for the q-omega workspace.
QAxisBinning Input dbl list Mandatory The bin parameters to use for the q axis (in the format used by the Rebin v1 algorithm).
EMode Input string Mandatory The energy transfer analysis mode (Direct/Indirect). Allowed values: [‘Direct’, ‘Indirect’]
EFixed Input number 0 The value of fixed energy: E_i (EMode=Direct) or E_f (EMode=Indirect) (meV). Must be set here if not available in the instrument definition.
ReplaceNaNs Input boolean False If true, all NaN values in the output workspace are replaced using the ReplaceSpecialValues algorithm.

Description

Converts a 2D workspace in units of spectrum number/energy transfer to the intensity as a function of momentum transfer Q and energy transfer \Delta E.

The rebinning is done as a weighted sum of overlapping polygons. See SofQWCentre v1 for centre-point binning or SofQWNormalisedPolygon v1 for more complex and precise (but slower) binning strategy.

Usage

Example - simple transformation of inelastic workspace:

# create sample inelastic workspace for MARI instrument containing 1 at all spectra values
ws=CreateSimulationWorkspace(Instrument='MAR',BinParams='-10,1,10')
# convert workspace into MD workspace
ws=SofQWPolygon(InputWorkspace=ws,QAxisBinning='-3,0.1,3',Emode='Direct',EFixed=12)

print "The converted X-Y values are:"
Xrow=ws.readX(59);
Yrow=ws.readY(59);
for i in xrange(0,20):
 print '! {0:>6.2f} {1:>6.2f} '.format(Xrow[i],Yrow[i]),
 if (i+1)%10 == 0:
     print '!\n',
print '! {0:>6.2f} ------- !'.format(Xrow[20]),

Output:

The converted X-Y values are:
! -10.00  12.79  !  -9.00  17.63  !  -8.00  17.86  !  -7.00  18.12  !  -6.00  18.46  !  -5.00  18.69  !  -4.00  19.24  !  -3.00  19.67  !  -2.00  18.49  !  -1.00  12.00  !
!   0.00  17.08  !   1.00  22.32  !   2.00  23.26  !   3.00  24.46  !   4.00  25.96  !   5.00  21.96  !   6.00  25.10  !   7.00  33.65  !   8.00  35.54  !   9.00  43.86  !
!  10.00 ------- !

Categories: Algorithms | Inelastic\SofQW

Source

C++ source: SofQWPolygon.cpp

C++ header: SofQWPolygon.h