Update of practice - 26-04-2014, 17:44

Author: jdelicado

cachematrix.R

@@ -1,23 +1,41 @@
 ## Put comments here that give an overall description of what your
 ## functions do
 
+##### Calculate de inverse matrix, storing this matrix to avoid its calculation again
+
+
+
 ## Write a short comment describing this function
 
+##### makeCacheMatrix
+#####
+##### Store the data of a created matrix. The store is composed to a list with 4 elements:
+#####   1 - assingment of the matrix (set)
+#####   2 - show the matrix (get)
+#####   3 - calculate de inverse matrix (setinverse)
+#####   4 - show the inverse matrix (getinverse)
+
 makeCacheMatrix <- function(x = matrix()) {
-	cachedmatrix <- NULL
-	set <- function(y) {
+  cachedmatrix <- NULL                # create an empty object, which is used to store the returned values
+  
+  set <- function(y) {                # create a function to assign the value of the matrix
             x <<- y
-	          cachedmatrix <<- NULL
-        	  }
-  get <- function() {
+            cachedmatrix <<- NULL
+            }
+  
+  get <- function() {                 # create a function to show the matrix
             x
-		        }
-  setinverse <- function(solve) {
-			              cachedmatrix <<- solve
-			              }
-  getinverse <- function() {
-			            cachedmatrix
-			            }
+            }
+  
+  setinverse <- function(solve) {     # create a function to calculate the inverse matrix
+                    cachedmatrix <<- solve
+                    }
+  
+  getinverse <- function() {          # create a function to show the inverse matrix
+                  cachedmatrix
+                  }
+  
+  # create a list, which elements are been described above
   list(set = set, get = get,
        setinverse = setinverse,
        getinverse = getinverse)
@@ -26,16 +44,24 @@ makeCacheMatrix <- function(x = matrix()) {
 
 ## Write a short comment describing this function
 
+##### Calculate the invese matrix. In the case, it is the first time, it calculates the
+##### inverse matrix, else it returns the inverse matrix calculated previously, which is
+##### obtained calling getinverse() function.
+
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
-
-	cachedmatrix <- x$getinverse()
-        if(!is.null(cachedmatrix)) {
-            message("getting cached data")
-            return(cachedmatrix)
-        }
-        data <- x$get()
-        cachedmatrix <- solve(data)
-        x$setinverse(cachedmatrix)
-        cachedmatrix
+  ## Return a matrix that is the inverse of 'x'
+
+  cachedmatrix <- x$getinverse()   # obtain the inverse matrix
+  
+  # if it was calculated previously (x$getinverse() returns the inverse matrix)
+  if(!is.null(cachedmatrix)) {
+      message("getting cached data")
+      return(cachedmatrix)      # return the inverse matrix
+      }
+  
+  # else
+  data <- x$get()               # if the inverse matrix was not calculated previously
+  cachedmatrix <- solve(data)   # calculate the inverse matrix
+  x$setinverse(cachedmatrix)    # store the inverse matrix in the list
+  cachedmatrix                  # return the inverse matrix
 }