R/plot_gp.R

In rumenGP: Rumen Gas Production Modeling, Comparison, and Visualization

#' Plot Raw Gas Production Curve
#'
#' Plots observed gas production measurements
#' for an individual bottle.
#'
#' This visualization displays the raw gas
#' production profile prior to model fitting and
#' is useful for:
#'
#' \itemize{
#'   \item Inspecting fermentation dynamics
#'   \item Identifying unusual observations
#'   \item Evaluating data quality
#'   \item Comparing individual bottle profiles
#' }
#'
#' @param data A \code{rumen_gp} object.
#'
#' @param head Bottle identifier to plot.
#'
#' @examples
#'
#' files <- example_data()
#'
#' raw_data <- read_ankom(
#'   files$ankom
#' )
#'
#' metadata <- read_metadata(
#'   files$metadata
#' )
#'
#' gp <- process_ankom(
#'   raw_data,
#'   metadata,
#'   headspace_ml = 210,
#'   temperature_c = 39
#' )
#'
#' plot_gp(
#'   gp,
#'   head = 1
#' )
#'
#' @return A \code{ggplot2} object.
#'
#' @seealso
#' \code{\link{plot_fit}},
#' \code{\link{plot_residuals}},
#' \code{\link{process_ankom}}
#'
#' @export
plot_gp <- function(
    data,
    head
) {

  if (!inherits(data, "rumen_gp")) {
    stop(
      "Input must be a rumen_gp object."
    )
  }

  df <- data |>
    dplyr::filter(
      Head == as.character(head)
    )

  if (nrow(df) == 0) {

    stop(
      paste(
        "Head",
        head,
        "was not found."
      )
    )

  }

  ggplot2::ggplot(
    df,
    ggplot2::aes(
      x = Time_h,
      y = Gas_mL
    )
  ) +

    ggplot2::geom_point(
      size = 2
    ) +

    ggplot2::geom_line() +

    ggplot2::labs(
      title = paste(
        "Raw gas production - Head",
        head
      ),
      x = "Time (h)",
      y = "Gas production (mL)"
    ) +

    ggplot2::theme_minimal()

}