From ec4c7c8cf0b6a912b7c8797ba911d47b8b3b86bd Mon Sep 17 00:00:00 2001
From: Paulo Schneider <paulo.schneider@gmail.com>
Date: Wed, 15 Jul 2015 18:04:59 +0100
Subject: [PATCH] Cache inverse of a matrix

---
 cachematrix.R | 35 +++++++++++++++++++++++++++--------
 1 file changed, 27 insertions(+), 8 deletions(-)

diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..cf1d1589c64 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,15 +1,34 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
+## This file provides a set of functions for caching the inverse of a matrix, for performance reasons.
 
+## Creates an object that represents a cached matrix. It exposes the following functions:
+## - set: set the value of the matrix
+## - get: get the value of the matrix
+## - setinverse: set the inverse of the matrix
+## - getinverse: get the inverse of the matrix
 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
-
+## Returns the inverse of a matrix, preferabily through its cached value.
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+  inverse <- x$getinverse()
+  if(!is.null(inverse)) {
+    message("getting cached data")
+    return(inverse)
+  }
+  data <- x$get()
+  inverse <- solve(data, ...)
+  x$setinverse(inverse)
+  inverse  
 }