rsrings {rsdepth} | R Documentation |
Bivariate RS Rings
Description
Computes the Ray Shooting rings of a bivariate data set.
Usage
rsrings(pt, numofrings=c(5),clr=FALSE,...)
Arguments
pt |
The data as a matrix, data frame or list. If it is a matrix or data frame, then each row is viewed as one multivariate observation. If it is a list, all components must be numerical vectors of equal length (coordinates of observations). Only 2-dimensional data is acceptable in this version. |
numofrings |
Total number of rings expected. |
clr |
Boolean for whether colors are used or not. |
... |
Reserved for future use. |
Details
Finds out the an arbitrary point among the Ray Shooting median set of given point set. Current uses the brute-force algorithm on all O(n^4) possible points
in the arrangment of all possible lines in complete graph on pt
. For each point O(n log n) is used to find out depth so overall complexity of this algorithm is O(n^5 log n).
When approximation parameter is provided then algorithm tries to approximate by finding median of a uniform sample subset of pt of size 1/eps^2*log(1/eps). If this constant is more than the size of original set then eps value is ignored and exact median is calculate on original point set.
Value
Number of rings returned
Author(s)
Nabil Mustafa, Saurabh Ray, and Mudassir Shabbir.
References
N. Mustafa, S. Ray, and M. Shabbir, Statistical Data Depth of Pointsets in the Plane,in prep..
See Also
rsdepth
for depth function
Examples
## RS median of a two-dimensional data set
set.seed(617)
zz <- matrix(rnorm(60), nc = 2)
rsrings(zz)