Expression¶
Type: | string |
---|---|
Range: | [] |
Default: | -/- |
Appearance: | simple |
Excludes: | Function, Module |
This parameter is used to define a tensor field of type “magnetic potential” by means of a Python expression within the .jcm
input file. The syntax is the following:
MagneticPotential {
Python {
Expression = " ... # your python scripting
...
value = ... # set return value
"
# define one or more parameters
Parameter {
Name = "Para1"
...
}
Parameter {
Name = "Para2"
...
}
}
}
The string value Expression
has to be valid Python code and is interpreted in the following way:
- The NumPy-package is automatically imported when evaluating the expression.
- Any parameter as defined by a
Parameter
section is available within the Python expression as an NumPy object named accordingly to the value of the parameter Name. - The position and the time are available as NumPy objects name
X
andt
respectively. - For time-harmonic electromagnetic problems the angular frequency can be addressed by
EMOmega
, (EM
stands for electromagnetic). - The expression must define a NumPy object named
value
which contains the return value of appropriate shape (magnetic potential is a 3-vector). - Keep in mind the Python indentation rule.
For practical examples we refer to the following cases: