This function allows you to make arbitrary changes to how mizer works by allowing you to replace any mizer function with your own version. You should do this only as a last resort, when you find that you can not use the standard mizer extension mechanism to achieve your goal.

customFunction(name, fun)



Name of mizer function to replace


The custom function to use as replacement


If the function you need to overwrite is one of the mizer rate functions, then you should use setRateFunction() instead of this function. Similarly you should use setResource() to change the resource dynamics and setReproduction() to change the density-dependence in reproduction.

If you find that your goal really does require you to overwrite a mizer function, please also create an issue on the mizer issue tracker at to describe your goal, because it will be interesting to the mizer community and may motivate future improvements to the mizer functionality.

Note that customFunction() only overwrites the function used by the mizer code. It does not overwrite the function that is exported by mizer. This is clarified when you run the code in the Examples section.


if (FALSE) { fake_project <- function(...) "Fake" customFunction("project", fake_project) mizer::project(NS_params) # This will print "Fake" project(NS_params) # This will still use the old project() function # To undo the effect: customFunction("project", project) mizer::project(NS_params) # This will again use the old project() }