radarChart: A function to produce a radar chart designed for mapping...
In JosephCrispell/plotteR: A collection of functions to help with base R plotting

Given a set of skills and scores for expertise, the function produces a radar chart as a tool to map our skills status and progress.

radarChart(
  scores,
  names,
  levels,
  polygon.col = "red",
  polygon.alpha = 0.1,
  polygon.pch = 19,
  axisLabelPad = 1.2,
  circles = FALSE,
  add = FALSE,
  main = "",
  margins = c(3, 3, 3, 3),
  addPoints = FALSE,
  radar.col = grDevices::rgb(0, 0, 0, 0.5),
  radar.lty = 1,
  radar.lwd = 0.5,
  levels.font = 1,
  levels.cex = 1,
  labels.font = 2,
  labels.cex = 1,
  levelsAxesAngle = 0,
  levelsLabelsAngle = 0
)

`scores`	Numeric vector of scores for each skill provided
`names`	Vector of character strings providing the name of each skill
`levels`	Vector of labels for each skills level
`polygon.col`	The fill colour for the skills polygon. Default value is `"red"`.
`polygon.alpha`	The transparency of the fill colour for the skills polygon. Default value is 0.1.
`polygon.pch`	The shape of the points on skills polygon. Default value is 19. Ignored if `addPoints` is FALSE.
`axisLabelPad`	The spacing between the name of each skill and the radar chart. Default value is 1.2.
`circles`	A boolean value indicating whether to plot skills levels as polygons or circles. Default value is FALSE.
`add`	A boolean value indicating whether to create a new radar chart or add to an existing one. Default value is FALSE.
`main`	Plot title. Default value is empty.
`margins`	A numeric vector specifying the sizes of the margins in inches (bottom, left, top, right). Default value is `c(3,3,3,3)`.
`addPoints`	A boolean value indicating whether to plot points in skills polygon corners. Default value is FALSE.
`radar.col`	The colour of the skills levels. Default value is `rgb(0,0,0, 0.5)`.
`radar.lty`	The line type for the skills levels. Default value is 1.
`radar.lwd`	The line width for the skills levels. Default value is 0.5.
`levels.font`	The font of the skills levels labels. Default value is 1.
`levels.cex`	The size of the skills levels labels. Default value is 1.
`labels.font`	The font of the names of the skills. Default value is 2.
`labels.cex`	The size of the names of the skills. Default value is 1.
`levelsAxesAngle`	The angle of the skills levels axis. Default value is 0.
`levelsLabelsAngle`	The angle of the skills levels labels on skills levels axis. Default value is 0.

# Create a radar chart to map our current status for selected skills
radarChart(scores=c(4,3.5,2,3,3,3), 
           names=c("Programming", "Statistics", "Databases", "Projects",
                   "Web", "Versioning"),
           levels=c("Unaware","Aware","Working","Practitioner", "Expert"))

# Add to the radar chart where we aim to get to
radarChart(scores=c(4,3.75,3,4,3,4), 
           names=c("Programming", "Statistics", "Databases", "Projects",
                   "Web", "Versioning"),
           levels=c("Unaware","Aware","Working","Practitioner", "Expert"),
           polygon.col="blue", add=TRUE)

# Add a legend
legend("topright", 
       legend=c("Current", "Aim"), 
       text.col=c(rgb(1,0,0, 0.5), rgb(0,0,1, 0.5)), 
       bty="n", text.font=2, cex=1.5, xpd=TRUE)