cachematrix.R

## Chacing the Inverse of a Matrix

## makeCacheMatrix returnes a list of functions that cache the inverse of a matrix

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

## cacheSolve retrieves the inverse of a matrix from makeCacheMatrix if inverse
## has already been calculated or computes the inverse here. 
## (cacheSolve takes as an argument the returned object from makeCacheMatrix) 

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