cachematrix.R

## Together these functions cache the inverse of a matrix so that if that
## inverse has already been calculated, the inverse is simply returned rather
## than recalculated.

## The first function creates a matrix+ object where the cache of the inverse
## can be stored. 

makeCacheMatrix <- function(x = matrix()) {
    inv <- NULL
    set <- function(y) {
        x <<- y
        inv <<- NULL
    }
    get <- function() x
    setinverse <- function(solve) inv <<- solve
    getinverse <- function() inv
    list(set = set, get = get,
         setinverse = setinverse,
         getinverse = getinverse)
}

## The second function calculates the inverse if it is not already cached.

cacheSolve <- function(x, ...) {
    inv <- x$getinverse()
    if(!is.null(inv)) {
        message("getting cached data")
        return(inv)
    }
    data <- x$get()
    inv <- solve(data, ...)
    x$setinverse(inv)
    inv
}