Easy scatter plots over multiple times (T1, T2, T3)

Make nice scatter plots over multiple times (T1, T2, T3) easily.

Usage

plot_means_over_time(
  data,
  response,
  group,
  groups.order = "none",
  error_bars = TRUE,
  ytitle = NULL,
  legend.title = "",
  significance_stars,
  significance_stars_x,
  significance_stars_y,
  significance_bars_x,
  print_table = FALSE,
  verbose = FALSE
)

Arguments

data

The data frame.

response

The dependent variable to be plotted (e.g., c("variable_T1", "variable_T2", "variable_T3"), etc.).

group

The group by which to plot the variable

groups.order

Specifies the desired display order of the groups on the legend. Either provide the levels directly, or a string: "increasing" or "decreasing", to order based on the average value of the variable on the y axis, or "string.length", to order from the shortest to the longest string (useful when working with long string names). "Defaults to "none".

error_bars

Logical, whether to include 95% confidence intervals for means.

ytitle

An optional x-axis label, if desired. If NULL, will take the variable name of the first variable in response, and keep only the part of the string before an underscore or period.

legend.title

The desired legend title.

significance_stars

Vetor of significance stars to display on the plot (e.g,. c("*", "**", "***")).

significance_stars_x

Vector of where on the x-axis significance stars should appear on the plot (e.g., c(2.2, 3.2, 4.2)).

significance_stars_y

Vector of where on the y-axis significance stars should appear on the plot. The logic here is different than previous arguments. Rather than providing actual coordinates, we provide a list object with structure group 1, group 2, and time of comparison, e.g., list(c("group1", "group2", time = 2), c("group1", "group3", time = 3), c("group2", "group3", time = 4)).

significance_bars_x

Vector of where on the x-axis vertical significance bars should appear on the plot (e.g., c(2:4)).

print_table

Logical, whether to also print the computed table.

verbose

Logical, whether to also print a note regarding the meaning of the error bars.

Value

A scatter plot of class ggplot.

Details

Error bars are calculated using the method of Morey (2008) through Rmisc::summarySEwithin(), but raw means are plotted instead of the normed means. For more information, visit: http://www.cookbook-r.com/Graphs/Plotting_means_and_error_bars_(ggplot2).

References

Morey, R. D. (2008). Confidence intervals from normalized data: A correction to Cousineau (2005). Tutorials in Quantitative Methods for Psychology, 4(2), 61-64. doi:10.20982/tqmp.04.2.p061

Examples

data <- mtcars
names(data)[6:3] <- paste0("T", 1:4, "_var")
plot_means_over_time(
  data = data,
  response = names(data)[6:3],
  group = "cyl",
  groups.order = "decreasing"
)


# Add significance stars/bars
plot_means_over_time(
  data = data,
  response = names(data)[6:3],
  group = "cyl",
  significance_bars_x = c(3.15, 4.15),
  significance_stars = c("*", "***"),
  significance_stars_x = c(3.25, 4.5),
  significance_stars_y = list(c("4", "8", time = 3),
                              c("4", "8", time = 4)))

# significance_stars_y: List with structure: list(c("group1", "group2", time))