cachematrix.R

## These functions create a special matrix object that includes a cached matrix inverse
## When these fucntions are used to solve a matrix inverse, if the inverse is already cached,
## that is simply returned rather than solved.  This can save a lot of time, since matrix inversion
## is computationally intensive.

## This augments the standard matrix object with a cached inverse matrix.
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)
        
}


##  The following function calculates the inverse of the special "matrix" created with the above 
##  function. However, it first checks to see if the inverse has already been calculated. If so, 
##  it gets the mean 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, ...) {
        ## Return a matrix that is the inverse of 'x'
        i <- x$getinverse()
        if(!is.null(i)){
                message("getting cached data")
                return(i)
        }
        data <- x$get()
        i <- solve(data,...)
        x$setinverse(i)
        i
}