def dynamicsusceptibility(workspace,
temperature,
outputName=None,
zeroEnergyEpsilon=1e-6):
"""Convert :math:`S(Q,E)` to susceptibility :math:`\chi''(Q,E)`.
#. If the X units are not in DeltaE, the workspace is transposed
#. The Y data in *workspace* is multiplied by :math:`1 - e^{\Delta E / (kT)}`
#. Y data in the bin closest to 0 meV and within -*zeroEnergyEpsilon* < :math:`\Delta E` < *zeroEnergyEpsilon* is set to 0
#. If the input was transposed, transpose the output as well
:param workspace: a :math:`S(Q,E)` workspace to convert
:type workspace: :class:`mantid.api.MatrixWorkspace`
:param temperature: temperature in Kelvin
:type temperature: float
:param outputName: name of the output workspace. If :class:`None`, the output will be given some generated name.
:type outputName: str or None
:param zeroEnergyEpsilon: if a bin center is within this value from 0, the bin's value is set to zero.
:type zeroEnergyEpsilon: float
:returns: a :class:`mantid.api.MatrixWorkspace` containing :math:`\chi''(Q,E)`
"""
workspace = _normws(workspace)
if not _validate._isSofQW(workspace):
raise RuntimeError('Failed to calculate dynamic susceptibility. ' +
"The workspace '{}' does not look like a S(Q,E).".
format(str(workspace)))
horAxis = workspace.getAxis(0)
horUnit = horAxis.getUnit().unitID()
doTranspose = horUnit != 'DeltaE'
if outputName is None:
outputName = 'CHIofQW_{}'.format(str(workspace))
if doTranspose:
workspace = Transpose(workspace,
OutputWorkspace='__transposed_SofQW_',
EnableLogging=False)
c = 1e-3 * constants.e / constants.k / temperature
outWS = OneMinusExponentialCor(workspace,
OutputWorkspace=outputName,
C=c,
Operation='Multiply',
EnableLogging=False)
_removesingularity(outWS, zeroEnergyEpsilon)
if doTranspose:
outWS = Transpose(outWS,
OutputWorkspace=outputName,
EnableLogging=False)
DeleteWorkspace('__transposed_SofQW_', EnableLogging=False)
outWS.setYUnitLabel("Dynamic susceptibility")
return outWS
def dynamicsusceptibility(workspace, temperature, outputName=None, zeroEnergyEpsilon=1e-6):
"""Convert :math:`S(Q,E)` to susceptibility :math:`\chi''(Q,E)`.
#. If the X units are not in DeltaE, the workspace is transposed
#. The Y data in *workspace* is multiplied by :math:`1 - e^{\Delta E / (kT)}`
#. Y data in the bin closest to 0 meV and within -*zeroEnergyEpsilon* < :math:`\Delta E` < *zeroEnergyEpsilon* is set to 0
#. If the input was transposed, transpose the output as well
:param workspace: a :math:`S(Q,E)` workspace to convert
:type workspace: :class:`mantid.api.MatrixWorkspace`
:param temperature: temperature in Kelvin
:type temperature: float
:param outputName: name of the output workspace. If :class:`None`, the output will be given some generated name.
:type outputName: str or None
:param zeroEnergyEpsilon: if a bin center is within this value from 0, the bin's value is set to zero.
:type zeroEnergyEpsilon: float
:returns: a :class:`mantid.api.MatrixWorkspace` containing :math:`\chi''(Q,E)`
"""
workspace = _normws(workspace)
if not _validate._isSofQW(workspace):
raise RuntimeError('Failed to calculate dynamic susceptibility. '
+ "The workspace '{}' does not look like a S(Q,E).".format(str(workspace)))
horAxis = workspace.getAxis(0)
horUnit = horAxis.getUnit().unitID()
doTranspose = horUnit != 'DeltaE'
if outputName is None:
outputName = 'CHIofQW_{}'.format(str(workspace))
if doTranspose:
workspace = Transpose(workspace, OutputWorkspace='__transposed_SofQW_', EnableLogging=False)
c = 1e-3 * constants.e / constants.k / temperature
outWS = OneMinusExponentialCor(workspace, OutputWorkspace=outputName, C=c, Operation='Multiply', EnableLogging=False)
_removesingularity(outWS, zeroEnergyEpsilon)
if doTranspose:
outWS = Transpose(outWS, OutputWorkspace=outputName, EnableLogging=False)
DeleteWorkspace('__transposed_SofQW_', EnableLogging=False)
outWS.setYUnitLabel("Dynamic susceptibility")
return outWS
def plotSofQW(workspace, QMin=0., QMax=None, EMin=None, EMax=None, VMin=0., VMax=None, colormap='jet', colorscale='linear'):
"""Plot a 2D :math:`S(Q,E)` workspace.
:param workspace: a workspace to plot
:type workspace: str or :class:`mantid.api.MatrixWorkspace`
:param QMin: minimum :math:`Q` to include in the plot
:type QMin: float or None
:param QMax: maximum :math:`Q` to include in the plot
:type QMax: float or None
:param EMin: minimum energy transfer to include in the plot
:type EMin: float or None
:param EMax: maximum energy transfer to include in the plot
:type EMax: float or None
:param VMin: minimum intensity to show on the color bar
:type VMin: float or None
:param VMax: maximum intensity to show on the color bar
:type VMax: float or None
:param colormap: name of the colormap
:type colormap: str
:param colorscale: color map scaling: 'linear', 'log'
:type colorscale: str
:returns: a tuple of (:mod:`matplotlib.Figure`, :mod:`matplotlib.Axes`)
"""
workspace = _normws(workspace)
if not _validate._isSofQW(workspace):
logger.warning("The workspace '{}' does not look like proper S(Q,W) data. Trying to plot nonetheless.".format(str(workspace)))
qHorizontal = workspace.getAxis(0).getUnit().name() == 'q'
isSusceptibility = workspace.YUnitLabel() == 'Dynamic susceptibility'
figure, axes = subplots()
if QMin is None:
QMin = 0.
if QMax is None:
dummy, QMax = validQ(workspace)
if EMin is None:
if isSusceptibility:
EMin = 0.
else:
EMin, unusedEMax = _energylimits(workspace)
if EMax is None:
EAxisIndex = 1 if qHorizontal else 0
EAxis = workspace.getAxis(EAxisIndex).extractValues()
EMax = EAxis[-1]
if VMax is None:
vertMax = EMax if EMax is not None else numpy.inf
dummy, VMax = nanminmax(workspace, horMin=QMin, horMax=QMax, vertMin=EMin, vertMax=vertMax)
VMax /= 100.
if VMin is None:
VMin = 0.
colorNormalization = None
if colorscale == 'linear':
colorNormalization = matplotlib.colors.Normalize()
elif colorscale == 'log':
if VMin <= 0.:
if VMax > 0.:
VMin = VMax / 1000.
else:
raise RuntimeError('Cannot plot nonpositive range in log scale.')
colorNormalization = matplotlib.colors.LogNorm()
else:
raise RuntimeError('Unknown colorscale: ' + colorscale)
contours = axes.pcolor(workspace, vmin=VMin, vmax=VMax, distribution=True, cmap=colormap, norm=colorNormalization)
colorbar = figure.colorbar(contours)
if isSusceptibility:
colorbar.set_label(r"$\chi''(Q,E)$ (arb. units)")
else:
colorbar.set_label(r'$S(Q,E)$ (arb. units)')
if qHorizontal:
xLimits = {'left': QMin, 'right': QMax}
yLimits = {'bottom': EMin}
if EMax is not None:
yLimits['top'] = EMax
xLabel = r'$Q$ ($\mathrm{\AA}^{-1}$)'
yLabel = 'Energy (meV)'
else:
xLimits = {'left': EMin}
if EMax is not None:
xLimits['right'] = EMax
yLimits = {'bottom': QMin, 'top': QMax}
xLabel = 'Energy (meV)'
yLabel = r'$Q$ ($\mathrm{\AA}^{-1}$)'
axes.set_xlim(**xLimits)
axes.set_ylim(**yLimits)
axes.set_xlabel(xLabel)
axes.set_ylabel(yLabel)
_SofQWtitle(workspace, axes)
return figure, axes
def plotSofQW(workspace,
QMin=0.,
QMax=None,
EMin=None,
EMax=None,
VMin=0.,
VMax=None,
colormap='jet',
colorscale='linear'):
"""Plot a 2D :math:`S(Q,E)` workspace.
:param workspace: a workspace to plot
:type workspace: str or :class:`mantid.api.MatrixWorkspace`
:param QMin: minimum :math:`Q` to include in the plot
:type QMin: float or None
:param QMax: maximum :math:`Q` to include in the plot
:type QMax: float or None
:param EMin: minimum energy transfer to include in the plot
:type EMin: float or None
:param EMax: maximum energy transfer to include in the plot
:type EMax: float or None
:param VMin: minimum intensity to show on the color bar
:type VMin: float or None
:param VMax: maximum intensity to show on the color bar
:type VMax: float or None
:param colormap: name of the colormap
:type colormap: str
:param colorscale: color map scaling: 'linear', 'log'
:type colorscale: str
:returns: a tuple of (:mod:`matplotlib.Figure`, :mod:`matplotlib.Axes`)
"""
workspace = _normws(workspace)
if not _validate._isSofQW(workspace):
logger.warning(
"The workspace '{}' does not look like proper S(Q,W) data. Trying to plot nonetheless."
.format(str(workspace)))
qHorizontal = workspace.getAxis(0).getUnit().name() == 'q'
isSusceptibility = workspace.YUnitLabel() == 'Dynamic susceptibility'
figure, axes = subplots()
if QMin is None:
QMin = 0.
if QMax is None:
dummy, QMax = validQ(workspace)
if EMin is None:
if isSusceptibility:
EMin = 0.
else:
EMin, unusedEMax = _energylimits(workspace)
if EMax is None:
EAxisIndex = 1 if qHorizontal else 0
EAxis = workspace.getAxis(EAxisIndex).extractValues()
EMax = EAxis[-1]
if VMax is None:
vertMax = EMax if EMax is not None else numpy.inf
dummy, VMax = nanminmax(workspace,
horMin=QMin,
horMax=QMax,
vertMin=EMin,
vertMax=vertMax)
VMax /= 100.
if VMin is None:
VMin = 0.
colorNormalization = None
if colorscale == 'linear':
colorNormalization = matplotlib.colors.Normalize()
elif colorscale == 'log':
if VMin <= 0.:
if VMax > 0.:
VMin = VMax / 1000.
else:
raise RuntimeError(
'Cannot plot nonpositive range in log scale.')
colorNormalization = matplotlib.colors.LogNorm()
else:
raise RuntimeError('Unknown colorscale: ' + colorscale)
contours = axes.pcolor(workspace,
vmin=VMin,
vmax=VMax,
distribution=True,
cmap=colormap,
norm=colorNormalization)
colorbar = figure.colorbar(contours)
if isSusceptibility:
colorbar.set_label(r"$\chi''(Q,E)$ (arb. units)")
else:
colorbar.set_label(r'$S(Q,E)$ (arb. units)')
if qHorizontal:
xLimits = {'left': QMin, 'right': QMax}
yLimits = {'bottom': EMin}
if EMax is not None:
yLimits['top'] = EMax
xLabel = r'$Q$ ($\mathrm{\AA}^{-1}$)'
yLabel = 'Energy (meV)'
else:
xLimits = {'left': EMin}
if EMax is not None:
xLimits['right'] = EMax
yLimits = {'bottom': QMin, 'top': QMax}
xLabel = 'Energy (meV)'
yLabel = r'$Q$ ($\mathrm{\AA}^{-1}$)'
axes.set_xlim(**xLimits)
axes.set_ylim(**yLimits)
axes.set_xlabel(xLabel)
axes.set_ylabel(yLabel)
_SofQWtitle(workspace, axes)
return figure, axes