Serial axes coordinates

It is mainly used to visualize the high dimensional data set either on the parallel coordinate or the radial coordinate.

coord_serialaxes(
  axes.layout = c("parallel", "radial"),
  scaling = c("data", "variable", "observation", "none"),
  axes.sequence = character(0L),
  positive = TRUE,
  ...
)

Arguments

axes.layout

Serial axes layout, either "parallel" or "radial".

scaling

One of data, variable, observation or none (not suggested the layout is the same with data) to specify how the data is scaled.

axes.sequence

A vector with variable names that defines the axes sequence.

positive

If y is set as the density estimate, where the smoothed curved is faced to, right (positive) or left (negative) as vertical layout; up (positive) or down (negative) as horizontal layout?

...

other arguments used to modify layers

Value

a ggproto object

Details

Serial axes coordinate system (parallel or radial) is different from the Cartesian coordinate system or its transformed system (say polar in ggplot2) since it does not have a formal transformation (i.e. in polar coordinate system, "x = rcos(theta)", "y = rsin(theta)"). In serial axes coordinate system, mapping aesthetics does not really require "x" or "y". Any "non-aesthetics" components passed in the mapping system will be treated as an individual axis.

To project a common geom layer on such serialaxes, users can customize function add_serialaxes_layers.

Potential Risk

In package ggmulti, the function ggplot_build.gg is provided. At the ggplot construction time, the system will call ggplot_build.gg first. If the plot input is not a CoordSerialaxes coordinate system, the next method ggplot_build.ggplot will be called to build a "gg" plot; else some geometric transformations will be applied first, then the next method ggplot_build.ggplot will be executed. So, the potential risk is, if some other packages e.g. foo, also provide a function ggplot_build.gg that is used for their specifications but the namespace is beyond the ggmulti (ggmulti:::ggplot_build.gg is covered), error may occur. If so, please consider using the geom_serialaxes.

Examples

if(require("dplyr")) {
# Data
nba <- NBAstats2021 %>%
  mutate(
    dPTS = PTS - OPTS,
    dREB = REB - OREB,
    dAST = AST - OAST,
    dTO = TO - OTO
  )
# set sequence by `axes.sequence`
p <- ggplot(nba,
            mapping = aes(
              dPTS = dPTS,
              dREB = dREB,
              dAST = dAST,
              dTO = dTO,
              colour = Win
            )) +
       geom_path(alpha = 0.2) +
       coord_serialaxes(axes.layout = "radial") +
       scale_color_gradient(low="blue", high="red")
p
# quantile layer
p + geom_quantiles(quantiles = c(0.5),
                   colour = "green", linewidth = 1.2)

# facet
p +
  facet_grid(Playoff ~ CONF)
}