cohen_d_over_n function

Cohen's d as a function of sample size

Plot Cohen's d as sample size increases.

cohen_d_over_n(
  data = NULL,
  iv_name = NULL,
  dv_name = NULL,
  save_as_png = FALSE,
  png_name = NULL,
  xlab = NULL,
  ylab = NULL,
  width = 16,
  height = 9
)

Arguments

• data: a data object (a data frame or a data.table)

• iv_name: name of the independent variable (grouping variable)

• dv_name: name of the dependent variable (measure variable of interest)

• save_as_png: if save = TRUE, the plot will be saved as a PNG file.

• png_name: name of the PNG file to be saved. By default, the name will be "cohen_d_over_n_" followed by a timestamp of the current time. The timestamp will be in the format, jan_01_2021_1300_10_000001, where "jan_01_2021" would indicate January 01, 2021; 1300 would indicate 13:00 (i.e., 1 PM); and 10_000001 would indicate 10.000001 seconds after the hour.

• xlab: title of the x-axis for the histogram by group. If xlab = FALSE, the title will be removed. By default (i.e., if no input is given), dv_name will be used as the title.

• ylab: title of the y-axis for the histogram by group. If ylab = FALSE, the title will be removed. By default (i.e., if no input is given), iv_name will be used as the title.

• width: width of the plot to be saved. This argument will be directly entered as the width argument for the ggsave

  function within ggplot2 package (default = 16)

• height: height of the plot to be saved. This argument will be directly entered as the height argument for the ggsave

  function within ggplot2 package (default = 9)

Returns

the output will be a list of (1) ggplot object (histogram by group) and (2) a data.table with Cohen's d by sample size

Examples

## Not run:

cohen_d_over_n(data = mtcars, iv_name = "am", dv_name = "mpg")
## End(Not run)