Improve the usage of model fitting functions within a piped work flow.
Details
zfit makes it easier to use a piped workflow with functions that don’t
have the “correct” order of parameters (the first parameter of the
function does not match the object passing through the pipe).
The issue is especially prevalent with model fitting functions, such as
when passing and processing a data.frame (or tibble) before passing
them to lm() or similar functions. The pipe passes the data object
into the first parameter of the function, but the conventional
estimation functions expect a formula to be the first parameter.
This package addresses the issue with three functions that make it trivial to construct a pipe-friendly version of any function:
zfunction()reorders the arguments of a function. Just pass the name of a function, and the name of the parameter that should receive the piped argument, and it returns a version of the function with that parameter coming first.zfold()creates a fold (a wrapper) around a function with the reordered arguments. This is sometimes needed instead of a simple reordering, for example for achieving correct S3 dispatch, and for functions that report its name or other information in output.zfitter()takes any estimation function with the standard format of aformulaanddataparameter, and returns a version suitable for us in pipes (with thedataparameter coming first). Internally, it simply calls thezfold()function to create a fold around the fitter function.
The package also includes ready made wrappers around the most commonly
used estimation functions. zlm()and zglm() correspond to lm() and
glm(), and zlogit(), zprobit(), and zpoisson(), use glm() to
perform logistic or poisson regression within a pipe.
Finally, the package includes the zprint() function, which is intended
to simplify the printing of derived results, such as summary(), within
the pipe, without affecting the modeling result itself.