polyparse: Parsing marginal treatment response formulas

In ivmte: Instrumental Variables: Extrapolation by Marginal Treatment Effects

Description

This function takes in an MTR formula, and then parses the formula such that it becomes a polynomial in the unobservable u. It then breaks these polynomials into monomials, and then integrates each of them with respect to u. Each integral corresponds to E[md | D, X, Z].

Usage

polyparse(
  formula,
  data,
  uname = "u",
  env = parent.frame(),
  as.function = FALSE
)

Arguments

formula	the MTR.
data	data.frame for which we obtain E[md | D, X, Z] for each observation.
uname	variable name for unobservable used in declaring the MTR.
env	environment, the original environment in which the formula was declared.
as.function	boolean, if FALSE then a list of the polynomial terms are returned; if TRUE then a list of functions corresponding to the polynomials are returned.

Value

A list (of lists) of monomials corresponding to the original MTR (for each observation); a list (of lists) of the integrated monomials; a vector for the degree of each of the original monomials in the MTR; and a vector for the names of each variable entering into the MTR (note x^2 + x has only one term, x).

Examples

dtm <- ivmte:::gendistMosquito()

## Declare MTR functions
formula1 = ~ 1 + u
formula0 = ~ 1 + u

## Construct MTR polynomials
polynomials0 <- polyparse(formula = formula0,
                          data = dtm,
                          uname = u,
                          as.function = FALSE)

polynomials1 <- polyparse(formula = formula0,
                          data = dtm,
                          uname = u,
                          as.function = FALSE)

ivmte documentation built on Sept. 17, 2021, 5:06 p.m.