pynucastro.nucdata.partition_function module

pynucastro.nucdata.partition_function module#

Classes and methods for dealing with nuclear partition functions.

class pynucastro.nucdata.partition_function.PartitionFunction(nucleus, name, T9_points, log_pf_data, interpolant_order=3)[source]#

Bases: object

Store the tabulated data for the partition function for a specific nucleus, which can be combined with other (non-overlapping) partition functions by addition and evaluated for different temperature values.

Adding two PartitionFunction objects is implemented by simply appending the temperature and partition function arrays of the higher-temperature partition function to those of the lower-temperature partition function. If the temperature ranges overlap, however, an exception is generated.

If either of the PartitionFunction objects added have already had a spline interpolant constructed, then construct a new spline interpolant for the returned PartitionFunction of order equal to the maximum order of the added PartitionFunction objects.

Parameters:

  • nucleus (str) – The nucleus (e.g. "ni56")

  • name (str) – The name of the table on which the nucleus is read

  • T9_points (numpy.ndarray) – A sorted array of all the temperatures involved. This is in GK.

  • log_pf_data (numpy.ndarray) – An array with all the partition function values given in the same order as temperature. This is log(pf)

  • interpolant_order (int) – The interpolation spline order, must be between 1 and 5, inclusive

eval(T)[source]#

Compute the interpolated partition function value for the temperature T. Note this returns log(pf)

Parameters:

T (float) – temperature in K

Return type:

float

lower_temperature()[source]#

Return the lowest temperature [K] this object supports.

Return type:

float

plot(T_min=10000000.0, T_max=100000000000.0)[source]#

Plot the partition function as a function of T

Parameters:

  • T_min (float) – minimum temperature [K] to plot

  • T_max (float) – maximum temperature [K] to plot

Return type:

matplotlib.figure.Figure

upper_temperature()[source]#

Return the highest temperature [K] this object supports.

Return type:

float

class pynucastro.nucdata.partition_function.PartitionFunctionCollection(use_high_temperatures=True, use_set='frdm')[source]#

Bases: object

A collection of PartitionFunctionTable objects in a dictionary keyed by the name of the tables.

In our discussion we have two different sets of tables: FRDM and ETFSI-Q.

Variables:

  • use_high_temperatures – whether to incorporate the high-temperature data tables

  • use_set – selects between the FRDM ('frdm') and ETFSI-Q ('etfsiq') data sets.

get_nuclei()[source]#

Return a set of all the nuclei this collection supports.

get_partition_function(nuc)[source]#

Return the PartitionFunction object for a specific nucleus.

class pynucastro.nucdata.partition_function.PartitionFunctionTable(file_name)[source]#

Bases: object

Manage a partition function table file. A PartitionFunction object is constructed for each nucleus and stored in a dictionary keyed by the lowercase nucleus name in the form e.g. “ni56”. The table files are stored in the PartitionFunction subdirectory.

Variables:

  • name – the name of the table (as defined in the data file)

  • T9_points – an array of temperature values in [GK]

get_nuclei()[source]#

Return a set of the nuclei this table supports.

get_partition_function(nuc)[source]#

Return the PartitionFunction object for a specific nucleus.

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