quadrant: Give the Quadrant Number of Planar Points

In sfsmisc: Utilities from 'Seminar fuer Statistik' ETH Zurich

Give the Quadrant Number of Planar Points

Description

Determine the quadrant of planar points, i.e. in which of the four parts cut by the x- and y- axis the points lie. Zero values (i.e. points on the axes) are treated as if positive.

Usage

quadrant(x, y=NULL)

Arguments

x,y	numeric vectors of the same length, or x is an x-y structure and y=NULL, see xy.coords.

Value

numeric vector of same length as x (if that's a vector) with values in 1:4 indicating the quadrant number of the corresponding point.

Examples

xy <- as.matrix(expand.grid(x= -7:7, y= -7:7)); rownames(xy) <- NULL
(qu <- quadrant(xy))
plot(xy, col = qu+1, main = "quadrant() number", axes = FALSE)
abline(h=0, v=0, col="gray") # the x- and y- axis
text(xy, lab = qu, col = qu+1, adj = c(1.4,0))

sfsmisc documentation built on Aug. 10, 2023, 5:06 p.m.