kardl (version 0.1.1)

parseFormula: Extract Variables from a Formula

Description

The parseFormula() unction extracts and lists variables from specific parts of a formula, especially those within parentheses of specified function types. This enables users to isolate and analyze segments of a model formula, such as variables within custom functions, with an option to ignore case sensitivity in pattern matching.

Usage

parseFormula(formula_, matchPattern = "asym", ignore.case = FALSE)

Value

A list containing:

• Parsed variables: Variables that are located within the specified matchPattern part of the formula.

• Remaining model: The rest of the formula, excluding the parsed variables.

Arguments

formula_

The initial formula for the model, typically specified using R's formula syntax (e.g., y ~ x + f(x1 + x2)).

matchPattern

A string or vector of strings that specifies the function(s) in the formula from which to extract variables. For example, matchPattern = "f()" will target variables within f(...) in the formula.

ignore.case

Logical; if FALSE (default), pattern matching is case-sensitive; if TRUE, case is ignored during matching.

A logical value indicating whether pattern matching should be case-sensitive (FALSE) or case-insensitive (TRUE).

See Also

replaceValues, formula

Examples

# Identify variables within specific functions, such as 'asymS'
parsed<-parseFormula(y ~ x +det(s + d) + asymS(d + s),"asymS()")
parsed

 # Parse formulas containing various collection types like () or []
formula_ <- y ~ x +det(s -gg- d) + asymS(d2 -rr+ s)-mm[y1+y2+y3]+asym[k1+k2+k3]+trend-huseyin

# Extract variables in the 'asymS' function
parseFormula(formula_,"asymS")

# Use multiple functions to extract variables. If a specified function, such as "uuu",
# is not found, nothing is returned for it
a<-parseFormula(formula_,c("mm","det","uuu"))

 # To obtain variables not enclosed within any function, specify them directly
 parseFormula(formula_,c("trend","huseyin"))

# By default, 'parseFormula()' is case-sensitive.
# For case-insensitive matching, set 'ignore.case = TRUE'

parseFormula(formula_,"asyms", TRUE)