From b4f5c09d49f520f5148b51f1c7d9956dcbb023e2 Mon Sep 17 00:00:00 2001
From: newxcombr <newxhost@gmail.com>
Date: Sat, 17 Jan 2015 21:13:41 -0200
Subject: [PATCH 1/2] add code for makeCacheMatrix and cacheSolve functions

---
 cachematrix.R | 33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..9d6b9b95b77 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,15 +1,30 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
-
 makeCacheMatrix <- function(x = matrix()) {
-
+  inverse <- NULL
+  set <- function(y) {
+    x <<- y
+    inverse <<- NULL
+  }
+  get <- function() x
+  setinverse <- function(inv) inverse <<- inv
+  getinverse <- function() inverse
+  list(set = set, get = get,
+       setinverse = setinverse,
+       getinverse = getinverse)
 }
 
 
-## Write a short comment describing this function
-
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+  ## Return a matrix that is the inverse of 'x'
+  inverse <- x$getinverse()
+  if(!is.null(inverse)) {
+    message("getting cached inverse matrix")
+    return(inverse)
+  }
+  
+  data <- x$get()
+  message("computing inverse matrix")
+  inverse <- solve(data, ...)
+  x$setinverse(inverse)
+  inverse
 }
+

From 9575946af1c08db6764da2ea51ade9c92c00610d Mon Sep 17 00:00:00 2001
From: newxcombr <newxhost@gmail.com>
Date: Sat, 17 Jan 2015 21:40:15 -0200
Subject: [PATCH 2/2] add comments to methods

---
 cachematrix.R | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/cachematrix.R b/cachematrix.R
index 9d6b9b95b77..015246b815a 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,3 +1,11 @@
+#Creates a special "matrix" object that can cache its inverse
+# Args:
+#   x: a square invertible matrix object
+#
+# Returns:
+#   A special "matrix" based on a list object that provides 
+#   a get/set methods to the original matrix object and a
+#   get/set methods to the inversed (and cached) matrix
 makeCacheMatrix <- function(x = matrix()) {
   inverse <- NULL
   set <- function(y) {
@@ -12,7 +20,14 @@ makeCacheMatrix <- function(x = matrix()) {
        getinverse = getinverse)
 }
 
-
+# Checks whether or not whe have a cached inversed matrix. 
+# Returns the cached object if found, otherwise computes the inverse matrix using R "solve" method
+#
+# Args:
+#   x: a square invertible matrix object
+#
+# Returns:
+#   An inverse matrix of x matrix (cached or computed)
 cacheSolve <- function(x, ...) {
   ## Return a matrix that is the inverse of 'x'
   inverse <- x$getinverse()