condvis (version 0.2-2)

dist1: Distance function

Description

Calculates Minkowski distance between a single point and a set of other points. (The actual returned value is distance^p to save on computation.)

Usage

dist1(x, X, p = 2, inf = FALSE)

Arguments

x

vector describing a point

X

matrix with ncol(X) == length(x), defining points to calculate distance from x

p

power to use in Minkowski distance, defaults to 2 for Euclidean distance.

inf

if TRUE function returns the l-infinity distance, also known as maximum norm distance.

Value

• A numeric vector.

Examples

x <- runif(5000)
y <- runif(5000)

x1 <- 0.5
y1 <- 0.5

par(mfrow = c(2, 2))

for(p in c(0.5, 1, 2, 10)){
    d <- dist1(x = c(x1, y1), X = cbind(x, y), p = p) ^ (1/p)
    col <- rep("black", length(x))
    col[d < 0.3] <- "red"
    plot(x, y, pch = 16, col = col, asp = 1, main = paste("p = ", p, sep = ""))
}