cachematrix.R

## R Programming Assignment 2: Lexical Scoping
## Provide functions that cache the inverse of a matrix

## This function creates a special "matrix" object that can cache its inverse.
makeCacheMatrix <- function(x = matrix()) {
    
    ## Fields
    # cached inverse value will be saved in this environment
    # x
    cachedInverse <- NULL
    
    ## Methods
    # Update the matrix
    set <- function(newValue) {
        x <<- newValue
        cachedInverse <<- NULL # Invalidate the cache
    }
    
    # Get the matrix
    get <- function() {
        x
    }
    
    # Update the cached inverse value
    setinverse <- function(inverse) {
        cachedInverse <<- inverse
    }
    
    # Get the cached inverse value
    getinverse <- function() {
        cachedInverse
    }
    
    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 the cachesolve should retrieve the inverse from
## the cache.
cacheSolve <- function(x, ...) {
    
    # try to get the cached value
    inverse <- x$getinverse()
    if (!is.null(inverse))
    {
        # if exist then return
        message("getting cached data")
        return(inverse)
    }

    # No cached inverse, do the compute and save it to cache
    inverse <- solve(x$get(), ...)
    x$setinverse(inverse)
    inverse
}