maxEmptyRect: Find an empty space on a plot

In plotrix: Various Plotting Functions

Find an empty space on a plot

Description

Try to find the largest empty rectangle on a plot.

Usage

 maxEmptyRect(ax,ay,x,y)

Arguments

ax,ay	The rectangle within which all of the points are contained. Usually the limits of a plot.
x,y	x and y positions of the points.

Details

‘⁠maxEmptyRect⁠’ searches the pairs of points on the plot to find the largest rectangular space within which none of the points lie. It does not guarantee that the space will be large enough to fit a legend or text.

Two alternatives are the ‘⁠largest.empty⁠’ function in the Hmisc package and the ‘⁠emptyspace⁠’ function. ‘⁠maxEmptyRect⁠’ appears to outperform ‘⁠emptyspace⁠’, particularly in running time. However, ‘⁠emptyspace⁠’ will sometimes find a "squarer" rectangle when ‘⁠maxEmptyRect⁠’ finds a slightly larger narrow rectangle.

Value

A list containing the area of the rectangle and the coordinates of the lower left and upper right corners (as used in ‘⁠rect⁠’) of the rectangle found.

Author(s)

Hans Borchers

References

A. Naamad, D. T. Lee, and W.-L. Hsu (1984). On the Maximum Empty Rectangle Problem. Discrete Applied Mathematics, 8: 267-277.

Examples

 x<-runif(100)
 y<-runif(100)
 plot(x,y,main="Find the maximum empty rectangle",xlab="X",ylab="Y")
 mer<-maxEmptyRect(c(0,1),c(0,1),x,y)
 rect(mer$rect[1],mer$rect[2],mer$rect[3],mer$rect[4],border="red")

plotrix documentation built on Nov. 10, 2023, 5:07 p.m.