rearrr (version 0.3.5)

flip_values: Flip the values around an origin

Description

lifecycle::badge("experimental")

The values are flipped with the formula \(`x = 2 * c - x`\) where x is the value and c is the origin coordinate to flip the values around.

The origin can be supplied as coordinates or as a function that returns coordinates. The latter can be useful when supplying a grouped data.frame and flipping around e.g. the centroid of each group. By default the median value in each dimension is used.

The *_vec() version take and return a vector.

Example:

The column values:

c(5, 2, 7, 4, 3, 1)

and the origin_fn = create_origin_fn(median)

Changes the values to :

c(2, 5, 0, 3, 4, 6)

Usage

flip_values(
  data,
  cols = NULL,
  origin = NULL,
  origin_fn = create_origin_fn(median),
  suffix = "_flipped",
  keep_original = TRUE,
  origin_col_name = ".origin",
  overwrite = FALSE
)
flip_values_vec(data, origin = NULL, origin_fn = create_origin_fn(median))

Arguments

data

data.frame or vector.

cols

Names of columns in `data` to flip values of.

origin

Coordinates of the origin to flip around. A scalar to use in all dimensions (columns) or a vector with one scalar per dimension.

N.B. Ignored when `origin_fn` is not NULL. Remember to set it to NULL when passing origin coordinates manually!

origin_fn

Function for finding the origin coordinates.

Input: Each column will be passed as a vector in the order of `cols`.

Output: A vector with one scalar per dimension.

Can be created with create_origin_fn() if you want to apply the same function to each dimension.

E.g. `create_origin_fn(median)` would find the median of each column.

Built-in functions are centroid(), most_centered(), and midrange()

suffix

Suffix to add to the names of the generated columns.

Use an empty string (i.e. "") to overwrite the original columns.

keep_original

Whether to keep the original columns. (Logical)

Some columns may have been overwritten, in which case only the newest versions are returned.

origin_col_name

Name of new column with the origin coordinates. If NULL, no column is added.

overwrite

Whether to allow overwriting of existing columns. (Logical)

Author

Ludvig Renbo Olsen,

See Also

Other mutate functions: apply_transformation_matrix(), cluster_groups(), dim_values(), expand_distances(), expand_distances_each(), roll_values(), rotate_2d(), rotate_3d(), shear_2d(), shear_3d(), swirl_2d(), swirl_3d()

Examples

# Attach packages
library(rearrr)
library(dplyr)
has_ggplot <- require(ggplot2)  # Attach if installed

# Set seed
set.seed(1)

# Create a data frame
df <- data.frame(
  "Index" = 1:10,
  "A" = sample(1:10),
  "B" = runif(10),
  "G" = c(
    1, 1, 1, 2, 2,
    2, 3, 3, 3, 3
  ),
  stringsAsFactors = FALSE
)

# Flip values of the columns
flip_values(df$A)
flip_values(df, cols = "A")
flip_values(df, cols = "B", origin = 0.3, origin_fn = NULL, keep_original = FALSE)
flip_values(df,
  cols = c("A", "B"),
  origin = c(3, 0.3),
  origin_fn = NULL,
  suffix = "",
  keep_original = FALSE,
  overwrite = TRUE
)
flip_values(df, cols = c("A", "B"), origin_fn = create_origin_fn(max))

# Grouped by G
df %>%
  dplyr::group_by(G) %>%
  flip_values(
    cols = c("A", "B"),
    origin_fn = create_origin_fn(median),
    keep_original = FALSE
  )

# Plot A and flipped A

# First flip A around the median and then around the value 3.
df <- df %>%
  flip_values(cols = "A", suffix = "_flip_median", origin_col_name = NULL) %>%
  flip_values(cols = "A", suffix = "_flip_3", origin = 3,
              origin_fn = NULL, origin_col_name = NULL)

# Plot A and A flipped around its median
if (has_ggplot){
  ggplot(df, aes(x = Index, y = A)) +
    geom_line(aes(color = "A")) +
    geom_line(aes(y = A_flip_median, color = "Flipped A (median)")) +
    geom_hline(aes(color = "Median A", yintercept = median(A))) +
    theme_minimal()
}

# Plot A and A flipped around the value 3
if (has_ggplot){
  ggplot(df, aes(x = Index, y = A)) +
    geom_line(aes(color = "A")) +
    geom_line(aes(y = A_flip_3, color = "Flipped A (3)")) +
    geom_hline(aes(color = "3", yintercept = 3)) +
    theme_minimal()
}