From ccf30862a20266830493ddfec14204028b2c8ba4 Mon Sep 17 00:00:00 2001
From: Marcus Teixeira <marcusvinct@yahoo.com.br>
Date: Sat, 24 May 2014 21:34:28 -0400
Subject: [PATCH 1/3] Functions makeCacheMatrix and cacheSolve completed.

---
 cachematrix.R | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..985000963e0 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -3,8 +3,23 @@
 
 ## Write a short comment describing this function
 
-makeCacheMatrix <- function(x = matrix()) {
-
+makeCacheMatrix <- function( dataMatrix = matrix() ) {
+    inverseMatrix <- NULL
+    
+    set <- function( newDataMatrix ) {
+        dataMatrix <<- newDataMatrix
+        inverseMatrix <<- NULL
+    }
+    
+    get <- function() dataMatrix
+    
+    setInverse <- function( inverse ) inverseMatrix <<- inverse
+    
+    getInverse <- function() inverseMatrix
+    
+    list(set = set, get = get,
+         setInverse = setInverse,
+         getInverse = getInverse)
 }
 
 
@@ -12,4 +27,13 @@ makeCacheMatrix <- function(x = matrix()) {
 
 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
 }

From ce7e05bc12f504b583ec538e3a234fe9f669f7f5 Mon Sep 17 00:00:00 2001
From: Marcus Teixeira <marcusvinct@yahoo.com.br>
Date: Sat, 24 May 2014 22:11:41 -0400
Subject: [PATCH 2/3] Comments added in.

---
 cachematrix.R | 55 ++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 43 insertions(+), 12 deletions(-)

diff --git a/cachematrix.R b/cachematrix.R
index 985000963e0..b3d776b81ca 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,39 +1,70 @@
-## Put comments here that give an overall description of what your
-## functions do
+## This program calculates the inverse of a Matrix. For efficiency' sake, it also leverages
+## a cache memory in order to avoid recalculating an inverse matrix previously done.
+##
+## Usage:
+##      1. Assign the makeCacheMatrix' returned Matrix to a variable
+##      2. Calculate its inverse Matrix using cacheSolve
+##      3. Call cacheSolve one more time to verify it is using a cache
+##      4. Clear cache redoing step 1 and repeat step 2 to check the cache is not used
+##
+## Example:
+##      1. matrixTest = makeCacheMatrix( matrix( c(2,0,1,3,0,0,5,1,1), nrow=3, ncol=3, byrow=TRUE ) )
+##      2. cacheSolve( matrixTest )
+##      3. cacheSolve( matrixTest )
+##      4. matrixTest = makeCacheMatrix( matrix( c(2,0,1,3,0,0,5,1,1), nrow=3, ncol=3, byrow=TRUE ) )
+##         cacheSolve( matrixTest )
+##
 
-## Write a short comment describing this function
+## makeCacheMatrix sets up an special Matrix object, which contains 2 variables
+## getters and setters functions for each one of them.
+## By default, the Matrix is initialized empty. Another matrix can be passed as parameter.
+## The inverse of a Matrix can only be calculated for a squared matrix, which means it has to have the same number of rows and columns.
+##
 
 makeCacheMatrix <- function( dataMatrix = matrix() ) {
     inverseMatrix <- NULL
     
+    ## Set the matrix
     set <- function( newDataMatrix ) {
-        dataMatrix <<- newDataMatrix
+        dataMatrix    <<- newDataMatrix
         inverseMatrix <<- NULL
     }
     
+    ## Get the matrix
     get <- function() dataMatrix
     
+    ## Set the inverse of the matrix
     setInverse <- function( inverse ) inverseMatrix <<- inverse
     
+    ## Get the inverse of the matrix
     getInverse <- function() inverseMatrix
     
-    list(set = set, get = get,
+    ## Return a list with all setter and getter functions
+    list(set = set,
+         get = get,
          setInverse = setInverse,
          getInverse = getInverse)
 }
 
 
-## Write a short comment describing this function
+## cacheSolve returns the inverse of a makeCacheMatrix object passed as parameter.
+## In case the inverse is stored in a cache, it returns the value stored there,
+## otherwise the inverse is calculated.
+## 
 
-cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
-    inverse <- x$getInverse()
+cacheSolve <- function( matrix, ... ) {
+    ## Verify the inverse matrix is cached
+    inverse <- matrix$getInverse()
+    
     if ( !is.null( inverse ) ) {
         message( "Getting cached data..." )
         return( inverse )
     }
-    data <- x$get()
+    
+    ## In case it is not cached, calculate it
+    data    <- matrix$get()
     inverse <- solve( data, ... )
-    x$setInverse( inverse )
+    matrix$setInverse( inverse )
+    
     inverse
-}
+}
\ No newline at end of file

From 9bd17aa4bb4fd5674692dfd33e8505d1436e431d Mon Sep 17 00:00:00 2001
From: Marcus Teixeira <marcusvinct@yahoo.com.br>
Date: Wed, 3 Sep 2014 00:27:01 -0400
Subject: [PATCH 3/3] Comments added in

---
 cachematrix.R | 1 +
 1 file changed, 1 insertion(+)

diff --git a/cachematrix.R b/cachematrix.R
index b3d776b81ca..973cf3752c3 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -17,6 +17,7 @@
 
 ## makeCacheMatrix sets up an special Matrix object, which contains 2 variables
 ## getters and setters functions for each one of them.
+##
 ## By default, the Matrix is initialized empty. Another matrix can be passed as parameter.
 ## The inverse of a Matrix can only be calculated for a squared matrix, which means it has to have the same number of rows and columns.
 ##