Implement memoized matrix inverse.

Author: sporkmonger

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
 }