Type: Package
Title: Create Subformulas of a Formula
Version: 0.1.0
Description: A formula 'sub' is a subformula of 'formula' if all the terms on the right hand side of 'sub' are terms of 'formula' and their left hand sides are identical. This package aids in the creation of subformulas.
License: MIT + file LICENSE
Encoding: UTF-8
LazyData: true
RoxygenNote: 6.1.1
Suggests: testthat, rmarkdown, knitr, covr
VignetteBuilder: knitr
URL: https://github.com/JonasMoss/subformula,
BugReports: https://github.com/JonasMoss/subformula/issues
NeedsCompilation: no
Packaged: 2019-11-12 16:25:04 UTC; jonas
Author: Jonas Moss ORCID iD [aut, cre]
Maintainer: Jonas Moss <jonas.gjertsen@gmail.com>
Repository: CRAN
Date/Publication: 2019-11-15 17:10:02 UTC

Apply Formulas to a Model

Description

fapply returns a list of the same length as formulas. Each element is the result of applying modelthe the corresponding element of formulas.

Usage

fapply(formulas, model, ...)

Arguments

formulas

a list of formulas or objects coercible to formula by stats::as.formula.

model

a function taking a formula as its first argument.

...

additional arguments to be passed to model.

Details

This is a member of the apply family. It is similar to lapply, but handles the call slightly differently. This makes the output prettier.

Value

fapply returns a list of evaluated function calls.

Examples

formulas = subformula(mpg ~ cyl + disp, protected = ~ cyl)
fapply(formulas, lm, data = mtcars) # Pretty output.
lapply(formulas, lm, data = mtcars) # Less pretty output.

Calculate Subformulas

Description

A formula sub is a subformula of formula if (i) all the terms on the right hand side of sub are terms of formula and (ii) their left hand sides are identical. subformula finds every subformula of formula that contains each term in protected.

Usage

subformula(formula, protected = NULL, data = NULL)

Arguments

formula

an object of class "formula" (or one that can be coerced to that class via formula).

protected

a vector or formula specifying which covariates are protected. Protected formulas appear in all subformulas.

data

an optional data frame (or object coercible by as.data.frame to a data frame). Used to fill out formulas as y ~ ..

Details

Protected terms will appear in every subformula. If the supplied formula includes the term 0 or -1, none of the subformulas will include the intercept. Otherwise, the intercept will be interpreted as being protected. If formula is is coerced to a formula object, its associated environment will be NULL. All subformulas will inherit their .Environment attribute from formula.

Value

subformula returns a list of formula objects.

Examples

subformula(z ~ x + y)
subformula(y ~ x + y + y^2, protected = ~ x)
subformula(y ~ x + y + t + I(t^2), protected = c("x","I(t^2)"))