1d:T4b7,# Creates polynomial terms for specified variables in a data frame Polynomial terms are named as `_d_` (e.g., `Z1_d_2` for the square of `Z1`). ```r add_poly_terms(data, Z, degree = 3, poly = TRUE) ``` ## Arguments - `data`: Data frame. The data frame containing the variables for which polynomial terms are to be created. - `Z`: Character vector. The names of the variables for which polynomial terms are to be created. - `degree`: Integer. The maximum degree of polynomial terms to be created. Default is 3. - `poly`: Logical. If TRUE, polynomial terms will be created. If FALSE, no polynomial terms will be created. Default is TRUE. ## Returns A list with two components: * `data`: The modified data frame with added polynomial terms. * `new_terms`: A character vector of the names of the added polynomial terms (e.g., `Z1_d_2`). #' ## Examples ```r set.seed(123) data_generator <- function(N){ Z1 <- rnorm(N,0,1) Z2 <- rnorm(N,0,1) X <- rnorm(N, Z1 + Z2, 1) Y <- rnorm(N, Z1 + Z2, 1) df <- data.frame(Z1, Z2, X, Y) return(df) } dat <- data_generator(250) poly_terms <- add_poly_terms(data = dat, Z = c("Z1", "Z2"), degree = 3, poly = TRUE) print(poly_terms$new_terms) ```1e:T49a,M7.49933 0.25C3.49635 0.25 0.25 3.49593 0.25 7.50024C0.25 10.703 2.32715 13.4206 5.2081 14.3797C5.57084 14.446 5.70302 14.2222 5.70302 14.0299C5.70302 13.8576 5.69679 13.4019 5.69323 12.797C3.67661 13.235 3.25112 11.825 3.25112 11.825C2.92132 10.9874 2.44599 10.7644 2.44599 10.7644C1.78773 10.3149 2.49584 10.3238 2.49584 10.3238C3.22353 10.375 3.60629 11.0711 3.60629 11.0711C4.25298 12.1788 5.30335 11.8588 5.71638 11.6732C5.78225 11.205 5.96962 10.8854 6.17658 10.7043C4.56675 10.5209 2.87415 9.89918 2.87415 7.12104C2.87415 6.32925 3.15677 5.68257 3.62053 5.17563C3.54576 4.99226 3.29697 4.25521 3.69174 3.25691C3.69174 3.25691 4.30015 3.06196 5.68522 3.99973C6.26337 3.83906 6.8838 3.75895 7.50022 3.75583C8.1162 3.75895 8.73619 3.83906 9.31523 3.99973C10.6994 3.06196 11.3069 3.25691 11.3069 3.25691C11.7026 4.25521 11

add_poly_terms function