berryFunctions (version 1.22.5)

distance: Distance between points

Description

Calculate distance between points on planar surface

Usage

distance(x, y, xref, yref, along = FALSE)

Value

vector with the distances

Arguments

x

vector with x-coordinate(s) of point(s)

y

ditto for y

xref

single x coordinate of reference point

yref

ditto for y

along

Logical: Should distances be computed along vector (x,y)? If TRUE, (xref,yref) are ignored. If both (xref,yref) are not given, along is set to TRUE.

Author

Berry Boessenkool, , 2012

Details

The function is quite simple: sqrt((xref - x)^2 + (yref - y)^2)

See Also

nndist in the package spatstat.geom for distance to nearest neighbour

Examples

A <- c(3,  9,-1)
B <- c(7, -2, 4)
plot(A,B)
text(A,B, paste0("P",1:3), adj=1.1)
points(3,5, col=2, pch=16)
segments(3,5, A,B)
distance(A,B, 3,5)
text(c(3.2,6,1), c(6,1,4), round(distance(A,B, 3,5),2) )