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 (data.frame/tibble) 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 or envelope) 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 a formula and data parameter, and returns a version suitable for us in pipes (with the data parameter coming first). Internally, it simply calls the zfold() 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(), as well as zlogit()]andzprobit(), andzpoisson()], to perform logistic or poisson regression within a pipe.

Finally, the package also includes the print() function, which is intended to simplify the printing of derived results, such as summary(), within the pipe, without affecting the modeling result itself.