f_expand: Formula interpolation

In jrnold/rubbish: Miscellaneous functions

Description

Formula interpolation to expand functions in a formula into lists of variables. The interpolation provided here are convenience functions for formulae used in modeling applications.

Usage

f_expand(f, lhs = TRUE, rhs = TRUE, envir = parent.frame())

Arguments

f	A formula
lhs	logical. Expand the left-hand side of the formula
rhs	logical. Expand the left-hand side of the formula
envir	An environment in which to evaluate the functions. This is where the expansion functions look for variable names.

Details

The following special interpolation functions are provided:

• .x(..., sep = "+") expands variables using the semantics in dplyr selection functions.

• .x_(..., sep = "+") is the standard evaluation version of .x

• .p(.f, sep = "+") matches all objects in envir that satisfy the predicate function .f

• .m(pattern, sep = "+") matches all names in envir that match the regular expression pattern.

Value

A formula object

See Also

See bquote and f_interp for other formula interpolation methods.

Examples

f_expand(~ .m("Sepal\\.*"), envir = iris)
f_expand(~ .x(everything()), envir = iris)
f_expand(~ .x(-Sepal.Width), envir = iris)
f_expand(~ .x(matches("Length"), -Sepal.Length), envir = iris)
f_expand(~ .p(is.numeric), envir = iris)
f_expand(~ .p(is.numeric, sep = "*"), envir = iris)

jrnold/rubbish documentation built on May 20, 2019, 2:05 a.m.