cachematrix.R

## The following functions are used to create a special object that
## stores a matrix and cache's its inverse

## Creates a special matrix that can 
## 1) get & set its value 
## 2) get & set its inverse 

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


## Retrieves the cached inverse of a matrix created with the preceding
## function. If the inverse is not cached, it first calculates and
## caches the inverse.

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