Implemented functions 'makeCacheMatrix' and 'cacheSolve'

Author: Julio Seaman

cachematrix.R

@@ -1,15 +1,67 @@
-## Put comments here that give an overall description of what your
-## functions do
+## The objective of this functions is to create a special structure which is
+## able to store a matrix and cache the value of its inverse the first time
+## it is needed. From then on as long as the values of the elements of the matrix
+## remain the same there is no need to recompute its inverse.
 
-## Write a short comment describing this function
+## "makeCacheMatrix" : creates a special matrix that includes the value of the original matrix
+## itself and the value of its inverse. The functions returns a list of functions
+## that set and get the value of the matrix and its inverse respectively.
 
 makeCacheMatrix <- function(x = matrix()) {
-
+    ## initiate inv with a NULL value
+    inv <- NULL
+    
+    ## set functions sets value y to x and sets inv to NULL again, 
+    ## thus, the inverse will have to be recomputed and cached again
+    set <- function(y) {
+        x <<- y
+        inv <<- NULL
+    }
+    
+    # returns the matrix
+    get <- function() x
+    
+    # sets the value of the inverse
+    setInverse <- function(inverse) inv <<- inverse
+    
+    # gets the value of the inverse
+    getInverse <- function() inv
+    
+    # #return a list with functions to get and set the matrix and its inverse
+    list(set = set, get = get,
+         setInverse = setInverse,
+         getInverse = getInverse)
 }
 
 
-## Write a short comment describing this function
+## "cacheSolve" : checks if the invere is already cached in memory. If it is the case
+## this value is returned. If not, the inverse is calculated and stored in memory
+## for future use.
 
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+    ## retrieves the value of the inverse stored in the CacheMatrix object
+    inv <- x$getInverse()
+    
+    ## First we check if the value is NOT null, meaning that it has been 
+    ## calculated previusly. If that is the case, we return the value
+    ## and we are done.
+    if(!is.null(inv)) {
+        message("getting cached data")
+        return(inv)
+    }
+    
+    ## If we reached this point, it means that the inverse of the matrix
+    ## has not been calculated yet. We need to retrieve the original matrix
+    ## from the CaheMatrix object
+    matrix <- x$get()
+    
+    ## The inverse is calculated. All additional parameters are passed to 
+    ## the function
+    inv <- solve(matrix, ...)
+    
+    ## We store the inverse for future uses
+    x$setInverse(inv)
+    
+    ## the calculated inverse is returned once it has been stored
+    inv
 }