v2frm {str2str}

Character Vector to Formula

Description

v2frm converts a character vector to a formula. The formula has the simple structure of y ~ x1 + x2 + x3 + ... + xn. This function is a simple wrapper for reformulate.

Usage

v2frm(v, y = 1L, intercept = TRUE)

Arguments

v

character vector of term(s) and/or response to be included on either side of the returned formula. If it is not a character vector (e.g., factor, numeric vector), then it is coerced to a character vector within v2frm. Note, if the length of v is 1, then y.which must be NULL because at least one term on the right hand side is required, otherwise an error is returned.

y

character vector of length 1 specifying the value of the element within v, or integer of length 1 specifying the position of the element within v, that is the response to be placed on the left hand side of the returned formula. If NULL, then no elements of v are treated as response(s) and the left hand side is empty.

intercept

logical vector of length 1 specifying whether the intercept should be included in the returned formula. The default is TRUE and no change is made to the returned formula. If FALSE, then a -1 is added to the end of the right hand side.

Value

formula with element v[y] on the left hand side and v[-y] elements on the right hand side (rhs) separated by plus signs (+) with a -1 if intercept = FALSE.

Examples

v2frm(v = names(attitude))
v2frm(v = names(attitude), y = 7L)
v2frm(v = names(attitude), y = NULL)
v2frm(v = "rating", y = NULL)
try_expr(v2frm(v = "rating")) # error is returned