# cdensity: Circular Density Curve In cplots: Plots for Circular Data

## Description

Function `cdensity` can be used to plot 2-dimensional density curves for circular data.

## Usage

 ```1 2 3``` ```cdensity(f, radius = 1/sqrt(base::pi), area.prop = TRUE, total.area = 1, nlabels = 4, add = FALSE, n = 500, col = "red", xlim = NULL, ylim = NULL, main = NULL) ```

## Arguments

 `f` an R function that is to be plotted as a circular density or frequency. `radius` the radius of the reference circle. If `radius = 0`, no reference circle is produced, and the centre presents the point with zero density. `area.prop` logical; if `TRUE`, an area-proportional transformation is applied; if `FALSE`, a height-proportional transformationis applied. `total.area` a positive number specifying the total area under the density curve. If `total.area = NULL`, no scaling is applied, the plot is in the original scale. If `area.prop = TRUE`, the total area is automatically unity without scaling. `nlabels` integer, for the number of levels to be plotted; if `0`, no label is plotted. `add` logical; if `TRUE`, the density curve is superimposed to the current plot, for example, a circular histogram, a rose diagram or a stacked dot plot that has been produced in a similar manner. `n` the number of points to plot the density curve. `col` the color of the density line. `xlim` numeric vectors of length 2, giving the x coordinates ranges. `ylim` numeric vectors of length 2, giving the y coordinates ranges. `main` the main title (on top)

## Author(s)

Danli Xu <dxu452@aucklanduni.ac.nz>, Yong Wang <yongwang@auckland.ac.nz>

## References

Xu, D. and Wang, Y. (2019) Area-proportional Visualization for Circular Data (submitted).

## See Also

`cbarplot`, `cdotplot`, `chist`

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18``` ```# 600 observations from two von Mises distributions library(circular) x = c(rvonmises(200, circular(pi/4), 5), rvonmises(400, circular(pi), 20)) dvm = function(x, mu=0, kappa=1) # von Mises density exp(kappa * cos(x - mu)) * (2 * pi * besselI(kappa, 0))^(-1) f = function(x) 1/3 * dvm(x, pi/4, 5) + 2/3 * dvm(x, pi, 20) cdensity(f) # plot the density in an area-proportional manner chist(x) # circular histogram cdensity(f, add=TRUE) # superimpose the density curve chist(x, area=FALSE) # height-proportional circular histogram cdensity(f, area=FALSE, add=TRUE) # superimpose the density curve chist(x, radius=0) # rose diagrams cdensity(f, radius=0, add=TRUE) chist(x, radius=0, area=FALSE) cdensity(f, radius=0, area=FALSE, add=TRUE) ```

cplots documentation built on May 2, 2019, 12:19 p.m.