cluster.overplot {plotrix} | R Documentation |
cluster.overplot
checks for overlying points in the x and y
coordinates passed. Those points that are overlying are moved to form
a small cluster of up to nine points. For large numbers of overlying
points, see count.overplot
or sizeplot
.
If you are unsure of the number of overplots in your data, run
count.overplot
first to see if there are any potential clusters
larger than nine.
cluster.overplot(x,y,away=NULL,tol=NULL,...)
x,y |
Numeric data vectors or the first two columns of a matrix or data frame. Typically the x/y coordinates of points to be plotted. |
away |
How far to move overlying points in user units. Defaults to the width of a lower case "o" in the x direction and 5/8 of the height of a lower case "o" in the y direction. |
tol |
The largest distance between points that will be considered to be overlying. Defaults to 1/2 of the width of a lower case "o" in the x direction and 1/2 of the height of a lower case "o" in the y direction. |
... |
additional arguments returned as they are passed. |
A list with two components. For unique x-y pairs the elements will be the same as in the original. For overlying points up to eight additional points will be generated that will create a cluster of points instead of one.
Jim Lemon
xy.mat<-cbind(sample(1:10,200,TRUE),sample(1:10,200,TRUE)) clusteredpoints<- cluster.overplot(xy.mat,col=rep(c("red","green"),each=100)) plot(clusteredpoints,col=clusteredpoints$col, main="Cluster overplot test")