The hardware and bandwidth for this mirror is donated by dogado GmbH, the Webhosting and Full Service-Cloud Provider. Check out our Wordpress Tutorial.
If you wish to report a bug, or if you are interested in having us mirror your free-software or open-source project, please feel free to contact us at mirror[@]dogado.de.

Plotting the Veterinary Examples

1 Plotting Principles

The original book uses simple black-and-white plots. In R, ggplot2 can recreate the same scientific comparisons with clearer labels and reproducible code. The goal is not decorative plotting; it is to show design structure, grouping, and model implications.

2 Split-Plot Packed Cell Volume Data

if (requireNamespace("collapse", quietly = TRUE) && requireNamespace("ggplot2", quietly = TRUE)) {
  ex124_plot <-
    ex124 |>
    collapse::fmutate(herd = factor(herd))

  ggplot2::ggplot(
    ex124_plot,
    ggplot2::aes(x = herd, y = PCVdif, shape = dose, color = drug)
  ) +
    ggplot2::geom_point(size = 2.4, position = ggplot2::position_jitter(width = 0.08)) +
    ggplot2::facet_wrap(~ drug, nrow = 1) +
    ggplot2::labs(
      x = "Herd",
      y = "Change in packed cell volume",
      shape = "Dose",
      color = "Drug",
      title = "Packed cell volume response by herd, drug, and dose"
    ) +
    ggplot2::theme_minimal()
}

3 Region, Drug, and Dose Means

if (requireNamespace("ggplot2", quietly = TRUE)) {
  ggplot2::ggplot(
    ex125,
    ggplot2::aes(x = dose, y = Pcv, group = Drug, color = Drug)
  ) +
    ggplot2::stat_summary(fun = mean, geom = "line") +
    ggplot2::stat_summary(fun = mean, geom = "point", size = 2.6) +
    ggplot2::facet_wrap(~ Region) +
    ggplot2::labs(
      x = "Dose",
      y = "Mean packed cell volume",
      title = "Mean response by region, drug, and dose"
    ) +
    ggplot2::theme_minimal()
}

4 Longitudinal PCV Data

if (requireNamespace("ggplot2", quietly = TRUE)) {
  ggplot2::ggplot(
    ex33,
    ggplot2::aes(x = time, y = PCV, group = animal_id, color = breed)
  ) +
    ggplot2::geom_line(linewidth = 0.5) +
    ggplot2::geom_point(size = 1.4) +
    ggplot2::labs(
      x = "Time",
      y = "Packed cell volume",
      color = "Breed",
      title = "Longitudinal packed cell volume by animal"
    ) +
    ggplot2::theme_minimal()
}

5 Model-Based Lines for Example 3.1

The book displays fitted lines for Example 3.1 Model 3. The packaged ex31 data can be plotted with simple group-specific linear fits to inspect the same relationship between baseline PCV and one-month PCV.

if (requireNamespace("collapse", quietly = TRUE) && requireNamespace("ggplot2", quietly = TRUE)) {
  ex31_plot <-
    ex31 |>
    collapse::fmutate(
      treatment = ifelse(drug == "BERENIL", paste(drug, dose), as.character(drug))
    )

  ggplot2::ggplot(
    ex31_plot,
    ggplot2::aes(x = PCV1, y = PCV2, color = treatment)
  ) +
    ggplot2::geom_point(size = 2) +
    ggplot2::geom_smooth(method = "lm", se = FALSE, linewidth = 0.8) +
    ggplot2::labs(
      x = "PCV at treatment",
      y = "PCV one month later",
      color = "Treatment",
      title = "Relationship between baseline and follow-up PCV"
    ) +
    ggplot2::theme_minimal()
}

These binaries (installable software) and packages are in development.
They may not be fully stable and should be used with caution. We make no claims about them.
Health stats visible at Monitor.