Transforms and Scales Numeric Points in a Data Frame by a Provided Factor and Direction

Usage

resizer(
  data = NULL,
  x,
  y,
  x_anchor = NULL,
  y_anchor = NULL,
  factor = NULL,
  direction = "up",
  drop = FALSE,
  ...
)

Arguments

data: A data frame or tibble with at least x and y variables.
x: A numeric variable in data. The variable intended to be plotted on the x axis in a ggplot.
y: A numeric variable in data. The variable intended to be plotted on the y axis in a ggplot.
x_anchor: A numeric value. The x coordinate point that the resized polygon will be scaled and anchored from. Default is the first x value in data.
y_anchor: A numeric value. The y coordinate that the resized polygon will be scaled and anchored from. Default is the first y value in data.
factor: A numeric value. The factor that will be used to resize the existing polygon in data.
direction: A string value of either "up" or "down. Data that is scaled "up" (default) will increase in size when plotted. Data that is scaled "down" will decrease in size.
drop: Logical TRUE or FALSE that determines if all other variables that are not being resized are removed from the final output. Default is FALSE.
...: Additional arguments passed to methods. Currently unused but reserved for future extensibility.

Value

A data frame

Examples

library(ggplot2)

# Resize a simple square "up" by a factor of 6
# Start with data that makes a shape#
df_square <-
  data.frame(
    x = c(0,1,1,0,0),
    y = c(0,0,1,1,0)
  )

# Resize the shape#
df_square_resized <-
  df_square |>
  resizer(x, y, factor = 6)

# Plot them
df_square |>
  ggplot(aes(x,y)) +
  # resized square - red dashed line
  geom_path(data = df_square_resized, color = "#a83246", linewidth = 2, linetype = 2) +
  # original square - black solid line
  geom_path(color = "#000000", linewidth = .8) +
  coord_equal()


# Resize a circle "down" by a factor of 3
df_circle <-
  circle_data(x = 5, y = 5, radius = 5, group_var = TRUE)

# Set then anchor point as the middle of the circle c(5,5)
# Although the point 5,5 is in the circle's bounds
# it's not actually a row in `df_circle`
# A message will display in cases like these and is "fine" to ignore.

df_circle_resized <-
  df_circle |>
  resizer(x,y, x_anchor = 5, y_anchor = 5, direction = "down", factor = 3)
#> ! The anchor point you've supplied (5, 5) is not found in your data.
#> ℹ The data will be scaled relative to this external point

# Plot them
df_circle |>
  ggplot(aes(x,y)) +
  # resized square - red dashed line
  geom_path(data = df_circle_resized, color = "#a83246", linewidth = 2, linetype = 2) +
  # original square - black solid line
  geom_path(color = "#000000", linewidth = .8) +
  coord_equal()