| Title: | Mathematical Operations on R Formula |
| Version: | 0.5.1 |
| Description: | Perform mathematical operations on R formula (add, subtract, multiply, etc.) and substitute parts of formula. |
| Depends: | R (≥ 3.5) |
| License: | GPL-3 |
| Encoding: | UTF-8 |
| RoxygenNote: | 7.3.2 |
| Suggests: | covr, spelling, testthat (≥ 3.0.0) |
| URL: | https://github.com/humanpred/formulops |
| BugReports: | https://github.com/humanpred/formulops/issues |
| Config/testthat/edition: | 3 |
| Language: | en-US |
| NeedsCompilation: | no |
| Packaged: | 2025-01-22 18:47:49 UTC; bill |
| Author: | Bill Denney  [aut,
cre] |
| Maintainer: | Bill Denney <wdenney@humanpredictions.com> |
| Repository: | CRAN |
| Date/Publication: | 2025-01-22 19:10:02 UTC |
Convert a substituting_formula object into a regular formula.
Description
Convert a substituting_formula object into a regular formula.
Usage
## S3 method for class 'substituting_formula'
formula(x, ...)
Arguments
x |
the substituting_formula object |
... |
Ignored |
Value
A formula with values substituted.
Extract formula parts
Description
Extract formula parts
Usage
get_lhs(x)
get_rhs(x)
Arguments
x |
A formula (or something that can be coerced to a formula) to extract a part from |
Value
The requested part of the formula as a name or call or NULL if
it does not exist.
Functions
-
get_lhs(): Extract the left hand side (NULL for one-sided formula). -
get_rhs(): Extract the right hand side.
Modify a formula by finding some part of it and replacing it with a new value.
Description
Modify a formula by finding some part of it and replacing it with a new value.
Usage
modify_formula(formula, find, replace, add_parens = FALSE)
Arguments
formula |
The formula to modify (may also be a call) |
find |
A call or name (or list thereof) to search for within the formula |
replace |
A call or name (or list thereof) to replace the |
add_parens |
Add parentheses if |
Details
Replacement occurs at the first match, so if the replacement list would modify something in the find list, that change will not occur (make two calls to the function for that effect). See the "Replacement is not sequential" examples below.
A special call can be used to expand a formula. If an expansion of arguments is desired to change a single function argument to multiple arguments, 'formulops_expand()' can be used. (See the examples.)
Value
formula modified
Examples
modify_formula(a~b, find=quote(a), replace=quote(c))
modify_formula(a~b, find=quote(a), replace=quote(c+d))
modify_formula(a~b/c, find=quote(b/c), replace=quote(d))
# Replacement is not sequential
modify_formula(a~b/c, find=list(quote(b/c), quote(d)), replace=list(quote(d), quote(e)))
modify_formula(a~b/c+d, find=list(quote(b/c), quote(d)), replace=list(quote(d), quote(e)))
# Expanding arguments to functions is possible
modify_formula(a~b(c), find=quote(c), replace=quote(formulops_expand(d, e)))
Perform a mathematical operation on two formula
Description
Perform a mathematical operation on two formula
Usage
op_formula(op, e1, e2)
multiply_formula(e1, e2)
divide_formula(e1, e2)
add_formula(e1, e2)
subtract_formula(e1, e2)
## S3 method for class 'formula'
Ops(e1, e2)
## S3 method for class 'formula'
Math(x, ...)
Arguments
op |
The operation to perform either as a name or something that can be coerced into a name. |
e1, e2, x |
The formulae to operate on |
... |
Ignored. |
Details
The method for combination depends if the two formula are one- or two-sided.
If both formula are one-sided, the right hand side (RHS) of both are added together with additional parentheses added, if parentheses appear to be needed. If both formula are two-sided, the left hand side (LHS) and RHS are separately added. If one formula is one-sided and the other is two-sided, the LHS is selected from the two-sided formula and the RHS follows rules as though two one-sided formula were added.
multiply_formula Multiply two formula (identical to (a~b) * (c~d)
divide_formula Divide two formula (identical to (a~b) / (c~d)
add_formula Add two formula (identical to (a~b) + (c~d)
subtract_formula Multiply two formula (identical to (a~b) - (c~d)
Ops.formula Supports generic binary operators and a couple of
unary operators (see ?Ops).
Math.formula Supports generic unary operators (see ?Math).
Value
e1 and e2 combined by the operation with the
environment from e1. See Details.
Examples
op_formula("+", a~b, c~d)
op_formula("+", a~b, ~d)
op_formula("+", ~b, c~d)
op_formula("+", ~b, ~d)
op_formula("-", a~b)
op_formula("-", -a~b) # Dumb, but accurate
op_formula("-", -a~b, c~-d) # Dumb, but accurate
log(a~b)
Remove extraneous parentheses from a formula.
Description
Remove extraneous parentheses from a formula.
Usage
simplify_parens(x)
Arguments
x |
The formula (or call) to simplify |
Value
The simplified formula
Examples
simplify_parens(((a))~((b+c)))
A substituting formula helps clarify a formula where the parameters are more simply described in separate formulae.
Description
A substituting formula helps clarify a formula where the parameters are more simply described in separate formulae.
Usage
substituting_formula(x, ...)
as_substituting_formula(x, substitutions)
Arguments
x |
The base formula |
... |
Supporting formula of the form |
substitutions |
A list of supporting formula. |
Details
Formula are substituted in order. Substitutions may not have the same left hand side.
Value
A substituting_formula object which may be coerced into a
single formula with an as.formula() method or printed as a list of
formulae.
Functions
-
as_substituting_formula(): Generate and check substituting_formula
Examples
foo <- substituting_formula(y~x1+x2, x1~x3*x4, x2~x5/x6+x7)
as.formula(foo)