From ac827f3c6d5023530865ccf27609a950ddc224a8 Mon Sep 17 00:00:00 2001
From: Christian Coughlan <christian.coughlan@gmail.com>
Date: Sat, 26 Apr 2014 09:33:01 -0400
Subject: [PATCH] completed makeCacheMatrix and cacheSolve functions

---
 cachematrix.R | 52 +++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 46 insertions(+), 6 deletions(-)

diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..144b2b84459 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,15 +1,55 @@
-## Put comments here that give an overall description of what your
-## functions do
+## The functions below are used create and cache the inverse of a matrix.
+## Matrix inversion is usually a costly computation and there may
+## be some benefit to caching the inverse of a matrix rather than
+## computing it repeatedly. 
 
-## Write a short comment describing this function
+## This function creates a special "matrix" object that can cache its inverse.
 
 makeCacheMatrix <- function(x = matrix()) {
+        myMatrix <- x
+        myInverseMatrix <- NULL
+        
+        ## sets the value of myMatrix
+        set <- function(y = matrix()) {
+                myMatrix <<- y                   
+        }
+        
+        ## gets the value of myMatrix
+        get <- function() {
+                myMatrix
+        }
+                
+        ## sets the value of myInverseMatrix
+        setInverse <- function(y = matrix()) {
+                myInverseMatrix <<- y
+        }
+                
+        ## gets the value of myInverseMatrix
+        getInverse <- function() {
+                myInverseMatrix
+        }
+        
+        ## returns a list of the functions
+        list(set = set, get = get,
+             setInverse = setInverse,
+             getInverse = getInverse)
 
 }
 
-
-## Write a short comment describing this function
+## This function computes the inverse of the special "matrix" 
+## returned by makeCacheMatrix above. If the inverse has already
+## been calculated (and the matrix has not changed), then cacheSolve
+## should retrieve the inverse from the cache.
 
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+        
+        i <- x$getInverse()         ## get the inverse from the matrix x         
+        if(!is.null(i)) {           ## if there is a cache (i.e. if cache is not null)
+                message("getting cached data") 
+                return(i)           ## return the cache
+        }
+        data <- x$get()             ## if the cache was null, get the matrix x
+        i <- solve(data, ...)       ## compute the inverse of x with solve()
+        x$setInverse(i)             ## cache the result
+        i                           ## Return a matrix that is the inverse of 'x'
 }