cachematrix.R

## Matrix inversion is usually a costly computation and there may be some
## benefit to caching the inverse of a matrix rather than computing it
## repeatedly. The following functions are used to cache the matrix.

## This function creates a special "matrix" object that can cache its inverse.

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


## This function computes the inverse of the special "matrix" returned by 
## `makeCacheMatrix` above. If the inverse has already been calculated 
## (and the matrix has not changed), then `cacheSolve` should retrieve the 
## inverse from the cache.

cacheSolve <- function(x, ...) {
  ## Return a matrix that is the inverse of 'x'
  m <- x$getinverse()
  if(!is.null(m)) {
    message("getting cached data")
    return(m)
  }
  data <- x$get()
  m <- solve(data, ...)
  x$setinverse(m)
  m
}