natural_logarithm#
- natural_logarithm(phase, X, A1=0.0, A2=1.0, A3=1.0, A4=0.0, A5=0.0)[source]#
Calculates the rate, as well as slope and intercept of the following function at the given value of X:
\[r = A_{1} Ln( A_{2} x^{ A_{3} }+ A_{4})+ A_{5}\]- Parameters:
phase (OpenPNM Phase object) – The phase object to which this model is associated (i.e. attached). This controls the length of the calculated array(s), and also provides access to other necessary properties.
X (str) – The dictionary key on the phase object containing the the quantity of interest
A5 (A1 ->) – The dictionary keys on the phase object containing the coefficients values to be used in the source term model
- Returns:
A dictionary containing the following three items:
- ’rate’
The value of the source term function at the given X.
- ’S1’
The slope of the source term function at the given X.
- ’S2’
The intercept of the source term function at the given X.
- Return type:
dict
Notes
The slope and intercept provide a linearized source term equation about the current value of X as follow:
\[rate = S_{1} X + S_{2}\]