From c9ff14d98fba05db8a99855169cf1b7d1d8080d6 Mon Sep 17 00:00:00 2001
From: Bob Aman <bob@sporkmonger.com>
Date: Sun, 7 Aug 2016 12:38:18 -0700
Subject: [PATCH] Implement memoized matrix inverse.

---
 cachematrix.R | 34 ++++++++++++++++++++++++----------
 1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..8576ea31d1f 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,15 +1,29 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
-
+## Creates a wrapped matrix that can memoize its inverse calculation.
 makeCacheMatrix <- function(x = matrix()) {
-
+        inv <- NULL
+        set <- function(y) {
+                x <<- y
+                inv <<- NULL
+        }
+        get <- function() x
+        setinverse <- function(inverse) inv <<- inverse
+        getinverse <- function() inv
+        list(set = set, get = get,
+             setinverse = setinverse,
+             getinverse = getinverse)
 }
 
-
-## Write a short comment describing this function
-
+## Memoized version of the matrix solve(x) function, which caches the result
+## of the inverse calculation.
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+          ## Return a matrix that is the inverse of 'x'
+          inv <- x$getinverse()
+          if(!is.null(inv)) {
+                  message("getting cached data")
+                  return(inv)
+          }
+          data <- x$get()
+          inv <- solve(data, ...)
+          x$setinverse(inv)
+          inv
 }