Layout Coordinates Utility Functions

Utility function used to manipulate layout coordinates. These functions always returns a tbl_df object.

Usage

center_layout_coordinates(layout)

normalize_layout_coordinates(layout)

project_layout_coordinates_on_unit_sphere(layout)

Arguments

layout

A matrix-like object with layout coordinates

Value

A tbl_df object with adjusted layout coordinates

Center Layout Coordinates

Centers each axis of the layout coordinates around their means.

Normalize Layout Coordinates

Centers each axis of the layout coordinates around the mean and adjusts each point coordinate such that their median length (euclidean norm) is 1.

Project Layout Coordinates on a Unit Sphere

Centers each axis of the layout coordinates around the mean and adjusts each coordinate such that their lengths (euclidean norm) are 1. This function only accepts layouts with 3 dimensions.

Examples

library(dplyr)
library(tibble)

# Generate random points that are offset to (100, 100, 100)
xyz <- matrix(rnorm(600, mean = 100, sd = 20), ncol = 3,
              dimnames = list(NULL, c("x", "y", "z"))) %>%
  as_tibble()

# Visualize random points
plotly::plot_ly(data = xyz, x = ~x, y = ~y, z = ~z,
                type = "scatter3d", mode = "markers")


# Center points at (0, 0, 0)
xyz_centered <- center_layout_coordinates(xyz)
apply(xyz_centered, 2, mean)
#>             x             y             z 
#>  4.477148e-15 -3.944505e-15 -4.049113e-15 
plotly::plot_ly(data = xyz_centered, x = ~x, y = ~y,
                z = ~z, type = "scatter3d", mode = "markers")


# Normalize points to have a median radius of 1
xyz_normalized <- normalize_layout_coordinates(xyz_centered)
radii <- sqrt(rowSums(xyz_normalized^2))
median(radii)
#> [1] 1
plotly::plot_ly(data = xyz_normalized, x = ~x, y = ~y,
                z = ~z, type = "scatter3d", mode = "markers")


# Project points on unit sphere
xyz_projected <- project_layout_coordinates_on_unit_sphere(xyz_normalized)
radii <- sqrt(rowSums(xyz_projected^2))
all(near(radii, y = rep(1, length(radii)), tol = 1e-12))
#> [1] TRUE
plotly::plot_ly(data = xyz_projected, x = ~x, y = ~y,
                z = ~z, type = "scatter3d", mode = "markers")