Frequency grid ggplot

NOTE: This function is currently experimental and shouldn't be relied upon.

Call frequency_grid_plot() to visualize the absolute frequencies of values in a vector. Each observation is plotted distinctly, resulting in a hybrid of a histogram and a scatterplot.

• Boxes are known values.

• Circles with NA labels are missing values.

• Empty circles are no values at all: They signify that certain unique values would have to be more frequent in order for all unique values to be equally frequent.

Usage

frequency_grid_plot(
  x,
  show_line_grid = FALSE,
  show_line_mode = FALSE,
  label_missing = "NA",
  color_label_missing = "red2",
  color_missing = "red2",
  color_non_missing = "blue2",
  alpha_missing = 1,
  alpha_non_missing = 0.75,
  size_label_missing = 3,
  size_missing = 10,
  size_non_missing = 10,
  shape_missing = 1,
  shape_non_missing = 15,
  expand = 0.1
)

Arguments

x

A vector with frequencies to visualize.

show_line_grid

Logical. Should gridlines be present, crossing at each observation? Default is FALSE.

show_line_mode

Logical. Should a dashed line demarcate the mode(s) among known values from the missing values that might add to these modes, if there are any? Default is FALSE.

label_missing

String. Label used for missing values. Default is "NA".

color_label_missing, color_missing, color_non_missing

String. Colors of the data points. Defaults are "red2" for missing data points as well as their labels, and "blue2" for non-missing data points.

alpha_missing, alpha_non_missing

Numeric. Opacity of the data points. Defaults are 1 and 0.75, respectively.

size_label_missing, size_missing, size_non_missing

Numeric. Sizes of the data points. Defaults are 3 for the label and 10 for both symbols.

shape_missing, shape_non_missing

Numeric or string. Signifiers for the shapes of the data points. Defaults are 1 (circle) and 15 (square filled), respectively.

expand

Numeric. Padding whitespace between the axes and the data points. The distance is the same on all four sides due to the grid structure. Default is 0.1.

Value

A ggplot object. To save it, call ggplot2::ggsave().

Limitations

Certain assumptions about missing values are currently hard-coded in the function. In the future, they should become optional. These assumptions are:

• All missings represent a known value. For example, in c(1, 2, NA), the NA is either 1 or 2.

• The missings are as evenly distributed across known values as possible. Therefore, in c(1, 2, NA, NA), one NA is a 1 and the other one is a 2. This is clearly not reasonable as a general assumption. It is derived from moder's way of determining possible extreme cases.

See also

frequency_grid_df(), which forms the basis of the current function.

Examples

x <- c("a", "a", "a", "b", "b", "c", NA, NA, NA, NA, NA)

# Basic usage:
frequency_grid_plot(x)


# With "N/A" as a marker of missing values
# instead of "NA":
frequency_grid_plot(x, label_missing = "N/A")


# Black and white mode:
frequency_grid_plot(
  x, color_label_missing = "black",
  color_missing = "black", color_non_missing = "black"
)