Model.new_macro#

Model.new_macro(name=None, formula=None)[source]#

Create a new Macro in this model.

Creates a macro that acts as a callable Python function saved within the model. Macros share a dedicated global namespace that includes the model itself as both mx_model and by the model’s name.

Parameters:

name (str, optional) – Name for the macro. If omitted and a function is provided, the function’s name is used. If the function name is not valid for a macro name, an error is raised. Must be a valid Python identifier, and must not start with an underscore.
formula (callable, optional) –
The function definition. Can be:
- A Python function (def or lambda)
- None to create an empty macro (not recommended)

Returns:

The newly created macro object

Return type:

Macro

Example

Creating a macro using new_macro:

>>> model = mx.new_model('MyModel')

>>> def get_model_info():
...     return f"Model: {mx_model._name}"

>>> model.new_macro(formula=get_model_info)
<Macro MyModel.get_model_info>

>>> model.get_model_info()
'Model: MyModel'

Above is equivalent to creating a macro using the decorator:

>>> @mx.defmacro
... def get_model_info():
...     return f"Model: {mx_model._name}"
<Macro MyModel.get_model_info>

Creating a macro with a custom name from a lambda function:

>>> model.new_macro('double', lambda x: x * 2)
<Macro MyModel.double>

>>> model.double(5)
10

Macros can call other macros in the same model:

>>> @mx.defmacro
... def helper():
...     return 42

>>> @mx.defmacro
... def main():
...     return helper() * 2

>>> model.main()
84