def subexp_eff(attenc, axis, scalec=None):
"""
This function calculates an efficiency from a subtracted exponential of the
form: c(1 - exp(-|k| * x)).
@param attenc: The attentuation constant k in the exponential.
@type attenc: L{hlr_utils.DrParameter}
@param axis: The axis from which to calculate the efficiency
@type axis: C{nessi_list.NessiList}
@param scalec: The scaling constant c applied to the subtracted
exponential.
@type scalec: L{hlr_utils.DrParameter}
@return: The calculated efficiency
@rtype: C{nessi_list.NessiList}
"""
import array_manip
import phys_corr
import utils
if scalec is None:
import hlr_utils
scalec = hlr_utils.DrParameter(1.0, 0.0)
axis_bc = utils.calc_bin_centers(axis)
temp = phys_corr.exp_detector_eff(axis_bc[0], scalec.getValue(),
scalec.getError(), attenc.getValue())
return array_manip.sub_ncerr(scalec.getValue(), scalec.getError(),
temp[0], temp[1])
def create_det_eff(obj, **kwargs):
"""
This function creates detector efficiency spectra based on the wavelength
spectra from the given object. The efficiency spectra are created based on
the following formalism: Ci*exp(-di*lambda) where i represents the
constants for a given detector pixel.
@param obj: Object containing spectra that will create the detector
efficiency spectra.
@type obj: C{SOM.SOM} or C{SOM.SO}
@param kwargs: A list of keyword arguments that the function accepts:
@keyword inst_name: The short name of an instrument.
@type inst_name: C{string}
@keyword eff_scale_const: Use this provided efficiency scaling constant.
@type eff_scale_const: L{hlr_utils.DrParameter}
@keyword eff_atten_const: Use this provided efficiency attenuation
constant.
@type eff_atten_const: L{hlr_utils.DrParameter}
@return: Object containing the detector efficiency spectra
@rtype: C{SOM.SOM} or C{SOM.SO}
@raise TypeError: Incoming object is not a C{SOM} or a C{SO}
@raise RuntimeError: The C{SOM} x-axis units are not I{Angstroms}
"""
# Check keywords
inst_name = kwargs.get("inst_name")
eff_scale_const = kwargs.get("eff_scale_const")
eff_atten_const = kwargs.get("eff_atten_const")
# set up for working through data
(result, res_descr) = hlr_utils.empty_result(obj)
o_descr = hlr_utils.get_descr(obj)
if o_descr != "SOM" and o_descr != "SO":
raise TypeError("Only SOM or SO objects permitted to create "\
+"efficiency spectra!")
# Check units on SOM, SO is assumed to be correct
if o_descr == "SOM":
if not obj.hasAxisUnits("Angstroms"):
raise RuntimeError("Incoming object must has a wavelength axis "\
+"with units of Angstroms!")
result = hlr_utils.copy_som_attr(result, res_descr, obj, o_descr)
# iterate through the values
import dr_lib
import phys_corr
import utils
# Get object length
len_obj = hlr_utils.get_length(obj)
for i in xrange(len_obj):
map_so = hlr_utils.get_map_so(obj, None, i)
axis = hlr_utils.get_value(obj, i, o_descr, "x", 0)
if inst_name is None:
axis_bc = utils.calc_bin_centers(axis)
(eff,
eff_err2) = phys_corr.exp_detector_eff(axis_bc[0], 1.0, 0.0, 1.0)
else:
if inst_name == "SANS":
(eff, eff_err2) = dr_lib.subexp_eff(eff_atten_const, axis,
eff_scale_const)
else:
raise RuntimeError("Do not know how to handle %s instrument" \
% inst_name)
hlr_utils.result_insert(result, res_descr, (eff, eff_err2), map_so)
return result
def create_det_eff(obj, **kwargs):
"""
This function creates detector efficiency spectra based on the wavelength
spectra from the given object. The efficiency spectra are created based on
the following formalism: Ci*exp(-di*lambda) where i represents the
constants for a given detector pixel.
@param obj: Object containing spectra that will create the detector
efficiency spectra.
@type obj: C{SOM.SOM} or C{SOM.SO}
@param kwargs: A list of keyword arguments that the function accepts:
@keyword inst_name: The short name of an instrument.
@type inst_name: C{string}
@keyword eff_scale_const: Use this provided efficiency scaling constant.
@type eff_scale_const: L{hlr_utils.DrParameter}
@keyword eff_atten_const: Use this provided efficiency attenuation
constant.
@type eff_atten_const: L{hlr_utils.DrParameter}
@return: Object containing the detector efficiency spectra
@rtype: C{SOM.SOM} or C{SOM.SO}
@raise TypeError: Incoming object is not a C{SOM} or a C{SO}
@raise RuntimeError: The C{SOM} x-axis units are not I{Angstroms}
"""
# Check keywords
inst_name = kwargs.get("inst_name")
eff_scale_const = kwargs.get("eff_scale_const")
eff_atten_const = kwargs.get("eff_atten_const")
# set up for working through data
(result, res_descr) = hlr_utils.empty_result(obj)
o_descr = hlr_utils.get_descr(obj)
if o_descr != "SOM" and o_descr != "SO":
raise TypeError("Only SOM or SO objects permitted to create "\
+"efficiency spectra!")
# Check units on SOM, SO is assumed to be correct
if o_descr == "SOM":
if not obj.hasAxisUnits("Angstroms"):
raise RuntimeError("Incoming object must has a wavelength axis "\
+"with units of Angstroms!")
result = hlr_utils.copy_som_attr(result, res_descr, obj, o_descr)
# iterate through the values
import dr_lib
import phys_corr
import utils
# Get object length
len_obj = hlr_utils.get_length(obj)
for i in xrange(len_obj):
map_so = hlr_utils.get_map_so(obj, None, i)
axis = hlr_utils.get_value(obj, i, o_descr, "x", 0)
if inst_name is None:
axis_bc = utils.calc_bin_centers(axis)
(eff, eff_err2) = phys_corr.exp_detector_eff(axis_bc[0], 1.0,
0.0, 1.0)
else:
if inst_name == "SANS":
(eff, eff_err2) = dr_lib.subexp_eff(eff_atten_const, axis,
eff_scale_const)
else:
raise RuntimeError("Do not know how to handle %s instrument" \
% inst_name)
hlr_utils.result_insert(result, res_descr, (eff, eff_err2), map_so)
return result
