pynucastro.rates.modified_rate module

class pynucastro.rates.modified_rate.ModifiedRate(original_rate, *, stoichiometry=None, new_reactants=None, new_products=None, update_screening=False)

Bases: Rate

A modified rate takes an original rate and changes some properties of it. The evaluation of the original rate will still be used for the actual rate, but the modified rate can have a different products (and therefore Q value) or stoichiometric coefficients

Parameters:

• original_rate (Rate) – the underlying rate we are evaluating numerically to get the number of reactions / sec (with suitable volume scalings)

• stoichiometry (dict(Nucleus)) – a custom set of coefficients to be used in the evolution equations dY(Nucleus)/dt. If this is not set, then simply the count of each nucleus in the list of reactants and products will be used.

• new_reactants (list(Nucleus)) – a list of nuclei that should be used as the reactants of the modified rate, instead of the reactants from the original rate.

• new_products (list(Nucleus)) – a list of nuclei that should be used as the products of the modified rate, instead of the products from the original rate.

• update_screening (bool) – do we reset the screening pairs for this rate to reflect any new products or stoichiometry? or do we still screen based on the underlying rate?

eval(T, *, rho=None, comp=None)

Evaluate the modified rate. This simply calls the evaluation of the underlying original rate.

Parameters:

• T (float) – the temperature to evaluate the rate at

• rho (float) – the density to evaluate the rate at

• comp (Composition) – the composition to evaluate the rate with

Return type:

float

function_string_cxx(dtype='double', specifiers='inline', leave_open=False, extra_args=())

Return a string containing C++ function that computes the approximate rate

function_string_py()

Return a string containing the python function that computes the rate – in this case it is the underlying original rate.

Return type:

str