cachematrix.R

## These pair of functions will cache the inverse of a matrix 
## (when is possible to do so)

## The first function, `makeCacheMatrix` creates a special 
## "matrix", which is really a list containing a function to 
## set the value of the matrix, get the ## value of the vector,
## set the value of the mean and get the value of the mean.

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


## The following function calculates the inverse of the 
## special "matrix" created with the first function. However, 
## it first checks to see if the inverse has already been 
## calculated. If so, it `get`s the inverse from the cache 
## and skips the computation. Otherwise, it calculates the
## inverse of the matrix and sets the value of the inverse 
## in the cache via the `setinverse` function.

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
}