Euclidean distance of two vectors

How do I find the Euclidean distance of two vectors:

x1 <- rnorm(30)
x2 <- rnorm(30)

Use the dist() function, but you need to form a matrix from the two inputs for the first argument to dist():

dist(rbind(x1, x2))

For the input in the OP's question we get:

> dist(rbind(x1, x2))
        x1
x2 7.94821

a single value that is the Euclidean distance between x1 and x2.

As defined on Wikipedia, this should do it.

euc.dist <- function(x1, x2) sqrt(sum((x1 - x2) ^ 2))

There's also the rdist function in the fields package that may be useful. See here.

EDIT: Changed ** operator to ^. Thanks, Gavin.

try using this:

sqrt(sum((x1-x2)^2))