R/convert_model_dots.R

In tylermorganwall/skpr: Design of Experiments Suite: Generate and Evaluate Optimal Designs

#'@title Converts dot operator to terms
#'
#'@description Converts the dot operator `.` in a formula to the linear terms in the model. Includes interactions (e.g. .*.)
#'@param design The design
#'@param model Base model
#'@param splitplotdesign split plot design data.frame
#'@return New model with dot operator replaced
#'@keywords internal
convert_model_dots = function(design, model, splitplotdesign = NULL) {
  if (
    any(
      unlist(strsplit(as.character(model[2]), "\\s\\+\\s|\\s\\*\\s|\\:|\\^")) ==
        "."
    )
  ) {
    if (is.null(splitplotdesign)) {
      dotreplace = paste0(
        "(",
        paste0(attr(design, "names"), collapse = " + "),
        ")"
      )
      additionterms = unlist(strsplit(as.character(model[2]), "\\s\\+\\s"))
      multiplyterms = unlist(lapply(
        lapply(
          strsplit(additionterms, split = "\\s\\*\\s"),
          gsub,
          pattern = "^\\.$",
          replacement = dotreplace
        ),
        paste0,
        collapse = " * "
      ))
      interactionterms = unlist(lapply(
        lapply(
          strsplit(multiplyterms, split = "\\:"),
          gsub,
          pattern = "^\\.$",
          replacement = dotreplace
        ),
        paste0,
        collapse = ":"
      ))
      powerterms = unlist(lapply(
        lapply(
          strsplit(interactionterms, split = "\\^"),
          gsub,
          pattern = "^\\.$",
          replacement = dotreplace
        ),
        paste0,
        collapse = "^"
      ))
      model = as.formula(paste0(
        "~",
        paste(powerterms, collapse = " + "),
        sep = ""
      ))
    } else {
      dotreplace = paste0(
        "(",
        paste(c(colnames(splitplotdesign), colnames(design)), collapse = " + "),
        ")"
      )
      additionterms = unlist(strsplit(as.character(model[2]), "\\s\\+\\s"))
      multiplyterms = unlist(lapply(
        lapply(
          strsplit(additionterms, split = "\\s\\*\\s"),
          gsub,
          pattern = "^\\.$",
          replacement = dotreplace
        ),
        paste0,
        collapse = " * "
      ))
      interactionterms = unlist(lapply(
        lapply(
          strsplit(multiplyterms, split = "\\:"),
          gsub,
          pattern = "^\\.$",
          replacement = dotreplace
        ),
        paste0,
        collapse = ":"
      ))
      powerterms = unlist(lapply(
        lapply(
          strsplit(interactionterms, split = "\\^"),
          gsub,
          pattern = "^\\.$",
          replacement = dotreplace
        ),
        paste0,
        collapse = "^"
      ))
      model = as.formula(paste0(
        "~",
        paste(powerterms, collapse = " + "),
        sep = ""
      ))
    }
  }
  return(model)
}