From 63d6df1fc7881a54f1ad1383c50b112ce92f1b78 Mon Sep 17 00:00:00 2001
From: Adam Benzan <adam.benzan@gmail.com>
Date: Mon, 17 Nov 2014 16:40:01 -0500
Subject: [PATCH 1/2] seems to work

---
 cachematrix.R | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..3140cf0cc74 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,15 +1,30 @@
-## Put comments here that give an overall description of what your
+  ## Put comments here that give an overall description of what your
 ## functions do
 
 ## Write a short comment describing this function
 
 makeCacheMatrix <- function(x = matrix()) {
-
+  m <- NULL
+  set <- function(y) {
+    x <<- y
+    m <<- NULL
+  }
+  get <- function() x
+  setinverse <- function(inverse) m <<- inverse
+  getinverse <- function() m
+  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'
+  m <- x$getinverse()
+  if (!is.null(m)) {
+    message('cached inverse')
+    return(m)
+  }
+  m <- solve(x$get())
+  x$setinverse(m)
+  m
 }

From 6b29f729a86ebcadd8a6bafff2aedda8f60545c1 Mon Sep 17 00:00:00 2001
From: Adam Benzan <adam.benzan@gmail.com>
Date: Mon, 17 Nov 2014 16:49:44 -0500
Subject: [PATCH 2/2] add comments

---
 cachematrix.R | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/cachematrix.R b/cachematrix.R
index 3140cf0cc74..6f958c6d465 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,30 +1,29 @@
-  ## Put comments here that give an overall description of what your
-## functions do
+## cachematrix: Functions to cache matrix inversion
 
-## Write a short comment describing this function
+## makeCacheMatrix sets up the scope for storing cache
 
 makeCacheMatrix <- function(x = matrix()) {
-  m <- NULL
-  set <- function(y) {
+  m <- NULL # initialize cache to NULL
+  set <- function(y) { # changing value invalidates cache
     x <<- y
     m <<- NULL
   }
-  get <- function() x
-  setinverse <- function(inverse) m <<- inverse
-  getinverse <- function() m
+  get <- function() x # return original matrix
+  setinverse <- function(inverse) m <<- inverse # set cache value to supplied value
+  getinverse <- function() m 
   list(set = set, get = get, setinverse=setinverse, getinverse=getinverse)
 }
 
-
-## Write a short comment describing this function
+## cacheSolve takes the list generated by makeCacheMatrix and either populates its cache
+## or returns the cached value
 
 cacheSolve <- function(x, ...) {
-  m <- x$getinverse()
+  m <- x$getinverse() # returns NULL if not yet cached
   if (!is.null(m)) {
-    message('cached inverse')
+    message('cached inverse') # report that returned value is from cache
     return(m)
   }
-  m <- solve(x$get())
+  m <- solve(x$get()) # uses solve to get inverse of x
   x$setinverse(m)
   m
 }