def calc_substrate_trans(obj, subtrans_coeff, substrate_diam, **kwargs):
"""
This function calculates substrate transmission via the following formula:
T = exp[-(A + B * wavelength) * d] where A is a constant with units of
cm^-1, B is a constant with units of cm^-2 and d is the substrate
diameter in units of cm.
@param obj: The data object that contains the TOF axes to calculate the
transmission from.
@type obj: C{SOM.SOM} or C{SOM.SO}
@param subtrans_coeff: The two coefficients for substrate transmission
calculation.
@type subtrans_coeff: C{tuple} of two C{float}s
@param substrate_diam: The diameter of the substrate.
@type substrate_diam: C{float}
@param kwargs: A list of keyword arguments that the function accepts:
@keyword pathlength: The pathlength and its associated error^2
@type pathlength: C{tuple} or C{list} of C{tuple}s
@keyword units: The expected units for this function. The default for this
function is I{microsecond}.
@type units: C{string}
@return: The calculate transmission for the given substrate parameters
@rtype: C{SOM.SOM} or C{SOM.SO}
@raise TypeError: The object used for calculation is not a C{SOM} or a
C{SO}
@raise RuntimeError: The C{SOM} x-axis units are not I{microsecond}
@raise RuntimeError: A C{SOM} does not contain an instrument and no
pathlength was provided
@raise RuntimeError: No C{SOM} is provided and no pathlength given
"""
# import the helper functions
import hlr_utils
# set up for working through data
(result, res_descr) = hlr_utils.empty_result(obj)
o_descr = hlr_utils.get_descr(obj)
if o_descr == "number" or o_descr == "list":
raise TypeError("Do not know how to handle given type: %s" % o_descr)
else:
pass
# Setup keyword arguments
try:
pathlength = kwargs["pathlength"]
except KeyError:
pathlength = None
try:
units = kwargs["units"]
except KeyError:
units = "microsecond"
# Primary axis for transformation. If a SO is passed, the function, will
# assume the axis for transformation is at the 0 position
if o_descr == "SOM":
axis = hlr_utils.one_d_units(obj, units)
else:
axis = 0
if pathlength is not None:
p_descr = hlr_utils.get_descr(pathlength)
else:
if o_descr == "SOM":
try:
obj.attr_list.instrument.get_primary()
inst = obj.attr_list.instrument
except RuntimeError:
raise RuntimeError("A detector was not provided")
else:
raise RuntimeError("If no SOM is provided, then pathlength "\
+"information must be provided")
result = hlr_utils.copy_som_attr(result, res_descr, obj, o_descr)
if res_descr == "SOM":
result.setYLabel("Transmission")
# iterate through the values
import array_manip
import axis_manip
import nessi_list
import utils
import math
len_obj = hlr_utils.get_length(obj)
for i in xrange(len_obj):
val = hlr_utils.get_value(obj, i, o_descr, "x", axis)
err2 = hlr_utils.get_err2(obj, i, o_descr, "x", axis)
map_so = hlr_utils.get_map_so(obj, None, i)
if pathlength is None:
(pl, pl_err2) = hlr_utils.get_parameter("total", map_so, inst)
else:
pl = hlr_utils.get_value(pathlength, i, p_descr)
pl_err2 = hlr_utils.get_err2(pathlength, i, p_descr)
value = axis_manip.tof_to_wavelength(val, err2, pl, pl_err2)
value1 = utils.calc_bin_centers(value[0])
del value
# Convert Angstroms to centimeters
value2 = array_manip.mult_ncerr(value1[0], value1[1],
subtrans_coeff[1]*1.0e-8, 0.0)
del value1
# Calculate the exponential
value3 = array_manip.add_ncerr(value2[0], value2[1],
subtrans_coeff[0], 0.0)
del value2
value4 = array_manip.mult_ncerr(value3[0], value3[1],
-1.0*substrate_diam, 0.0)
del value3
# Calculate transmission
trans = nessi_list.NessiList()
len_trans = len(value4[0])
for j in xrange(len_trans):
trans.append(math.exp(value4[0][j]))
trans_err2 = nessi_list.NessiList(len(trans))
hlr_utils.result_insert(result, res_descr, (trans, trans_err2), map_so)
return result
def tof_to_wavelength(obj, **kwargs):
"""
This function converts a primary axis of a C{SOM} or C{SO} from
time-of-flight to wavelength. The wavelength axis for a C{SOM} must be in
units of I{microseconds}. The primary axis of a C{SO} is assumed to be in
units of I{microseconds}. A C{tuple} of C{(tof, tof_err2)} (assumed to be
in units of I{microseconds}) can be converted to C{(wavelength,
wavelength_err2)}.
@param obj: Object to be converted
@type obj: C{SOM.SOM}, C{SOM.SO} or C{tuple}
@param kwargs: A list of keyword arguments that the function accepts:
@keyword pathlength: The pathlength and its associated error^2
@type pathlength: C{tuple} or C{list} of C{tuple}s
@keyword inst_param: The type of parameter requested from an associated
instrument. For this function the acceptable
parameters are I{primary}, I{secondary} and I{total}.
Default is I{primary}.
@type inst_param: C{string}
@keyword lojac: A flag that allows one to turn off the calculation of the
linear-order Jacobian. The default action is I{True} for
histogram data.
@type lojac: C{boolean}
@keyword units: The expected units for this function. The default for this
function is I{microseconds}.
@type units: C{string}
@return: Object with a primary axis in time-of-flight converted to
wavelength
@rtype: C{SOM.SOM}, C{SOM.SO} or C{tuple}
@raise TypeError: The incoming object is not a type the function recognizes
@raise RuntimeError: The C{SOM} x-axis units are not I{microseconds}
@raise RuntimeError: A C{SOM} does not contain an instrument and no
pathlength was provided
@raise RuntimeError: No C{SOM} is provided and no pathlength given
"""
# import the helper functions
import hlr_utils
# set up for working through data
(result, res_descr) = hlr_utils.empty_result(obj)
o_descr = hlr_utils.get_descr(obj)
# Setup keyword arguments
try:
inst_param = kwargs["inst_param"]
except KeyError:
inst_param = "primary"
try:
pathlength = kwargs["pathlength"]
except KeyError:
pathlength = None
try:
units = kwargs["units"]
except KeyError:
units = "microseconds"
try:
lojac = kwargs["lojac"]
except KeyError:
lojac = hlr_utils.check_lojac(obj)
# Primary axis for transformation. If a SO is passed, the function, will
# assume the axis for transformation is at the 0 position
if o_descr == "SOM":
axis = hlr_utils.one_d_units(obj, units)
else:
axis = 0
result = hlr_utils.copy_som_attr(result, res_descr, obj, o_descr)
if res_descr == "SOM":
result = hlr_utils.force_units(result, "Angstroms", axis)
result.setAxisLabel(axis, "wavelength")
result.setYUnits("Counts/A")
result.setYLabel("Intensity")
else:
pass
if pathlength is not None:
p_descr = hlr_utils.get_descr(pathlength)
else:
if o_descr == "SOM":
try:
obj.attr_list.instrument.get_primary()
inst = obj.attr_list.instrument
except RuntimeError:
raise RuntimeError("A detector was not provided")
else:
raise RuntimeError("If no SOM is provided, then pathlength "\
+"information must be provided")
# iterate through the values
import axis_manip
if lojac:
import utils
for i in xrange(hlr_utils.get_length(obj)):
val = hlr_utils.get_value(obj, i, o_descr, "x", axis)
err2 = hlr_utils.get_err2(obj, i, o_descr, "x", axis)
map_so = hlr_utils.get_map_so(obj, None, i)
if pathlength is None:
(pl, pl_err2) = hlr_utils.get_parameter(inst_param, map_so, inst)
else:
pl = hlr_utils.get_value(pathlength, i, p_descr)
pl_err2 = hlr_utils.get_err2(pathlength, i, p_descr)
value = axis_manip.tof_to_wavelength(val, err2, pl, pl_err2)
if lojac:
y_val = hlr_utils.get_value(obj, i, o_descr, "y")
y_err2 = hlr_utils.get_err2(obj, i, o_descr, "y")
counts = utils.linear_order_jacobian(val, value[0],
y_val, y_err2)
hlr_utils.result_insert(result, res_descr, counts, map_so,
"all", axis, [value[0]])
else:
hlr_utils.result_insert(result, res_descr, value, map_so,
"x", axis)
return result
def calc_substrate_trans(obj, subtrans_coeff, substrate_diam, **kwargs):
"""
This function calculates substrate transmission via the following formula:
T = exp[-(A + B * wavelength) * d] where A is a constant with units of
cm^-1, B is a constant with units of cm^-2 and d is the substrate
diameter in units of cm.
@param obj: The data object that contains the TOF axes to calculate the
transmission from.
@type obj: C{SOM.SOM} or C{SOM.SO}
@param subtrans_coeff: The two coefficients for substrate transmission
calculation.
@type subtrans_coeff: C{tuple} of two C{float}s
@param substrate_diam: The diameter of the substrate.
@type substrate_diam: C{float}
@param kwargs: A list of keyword arguments that the function accepts:
@keyword pathlength: The pathlength and its associated error^2
@type pathlength: C{tuple} or C{list} of C{tuple}s
@keyword units: The expected units for this function. The default for this
function is I{microsecond}.
@type units: C{string}
@return: The calculate transmission for the given substrate parameters
@rtype: C{SOM.SOM} or C{SOM.SO}
@raise TypeError: The object used for calculation is not a C{SOM} or a
C{SO}
@raise RuntimeError: The C{SOM} x-axis units are not I{microsecond}
@raise RuntimeError: A C{SOM} does not contain an instrument and no
pathlength was provided
@raise RuntimeError: No C{SOM} is provided and no pathlength given
"""
# import the helper functions
import hlr_utils
# set up for working through data
(result, res_descr) = hlr_utils.empty_result(obj)
o_descr = hlr_utils.get_descr(obj)
if o_descr == "number" or o_descr == "list":
raise TypeError("Do not know how to handle given type: %s" % o_descr)
else:
pass
# Setup keyword arguments
try:
pathlength = kwargs["pathlength"]
except KeyError:
pathlength = None
try:
units = kwargs["units"]
except KeyError:
units = "microsecond"
# Primary axis for transformation. If a SO is passed, the function, will
# assume the axis for transformation is at the 0 position
if o_descr == "SOM":
axis = hlr_utils.one_d_units(obj, units)
else:
axis = 0
if pathlength is not None:
p_descr = hlr_utils.get_descr(pathlength)
else:
if o_descr == "SOM":
try:
obj.attr_list.instrument.get_primary()
inst = obj.attr_list.instrument
except RuntimeError:
raise RuntimeError("A detector was not provided")
else:
raise RuntimeError("If no SOM is provided, then pathlength "\
+"information must be provided")
result = hlr_utils.copy_som_attr(result, res_descr, obj, o_descr)
if res_descr == "SOM":
result.setYLabel("Transmission")
# iterate through the values
import array_manip
import axis_manip
import nessi_list
import utils
import math
len_obj = hlr_utils.get_length(obj)
for i in xrange(len_obj):
val = hlr_utils.get_value(obj, i, o_descr, "x", axis)
err2 = hlr_utils.get_err2(obj, i, o_descr, "x", axis)
map_so = hlr_utils.get_map_so(obj, None, i)
if pathlength is None:
(pl, pl_err2) = hlr_utils.get_parameter("total", map_so, inst)
else:
pl = hlr_utils.get_value(pathlength, i, p_descr)
pl_err2 = hlr_utils.get_err2(pathlength, i, p_descr)
value = axis_manip.tof_to_wavelength(val, err2, pl, pl_err2)
value1 = utils.calc_bin_centers(value[0])
del value
# Convert Angstroms to centimeters
value2 = array_manip.mult_ncerr(value1[0], value1[1],
subtrans_coeff[1] * 1.0e-8, 0.0)
del value1
# Calculate the exponential
value3 = array_manip.add_ncerr(value2[0], value2[1], subtrans_coeff[0],
0.0)
del value2
value4 = array_manip.mult_ncerr(value3[0], value3[1],
-1.0 * substrate_diam, 0.0)
del value3
# Calculate transmission
trans = nessi_list.NessiList()
len_trans = len(value4[0])
for j in xrange(len_trans):
trans.append(math.exp(value4[0][j]))
trans_err2 = nessi_list.NessiList(len(trans))
hlr_utils.result_insert(result, res_descr, (trans, trans_err2), map_so)
return result