Finish assignment 2.

Author: basbossink

cachematrix.R

@@ -1,15 +1,39 @@
 ## Put comments here that give an overall description of what your
 ## functions do
-
+## makeCacheMatrix and cacheSolve can be used together to calculate the inverse
+## of a matrix and cache the result such that the inverse only has to be 
+## calculated once.
 ## Write a short comment describing this function
-
+## makeCacheMatrix creates a list that provides functionality to get and set 
+## the cached value of calculating the inverse of a matrix 
 makeCacheMatrix <- function(x = matrix()) {
-
+  inverse <- NULL
+  set <- function(new.x) {
+    x <<- new.x
+    inverse <<- NULL
+  }
+  get <- function() { x }
+  set.inverse <- function(new.inverse) { inverse <<- new.inverse }
+  get.inverse <- function() { inverse }
+  list(set = set, get = get,
+       set.inverse = set.inverse,
+       get.inverse = get.inverse)
 }
 
 
 ## Write a short comment describing this function
-
+## cacheSolve when given a list such as created by the makeCacheMatrix function
+## can calculate the inverse of the matrix and cache the result such that it 
+## only has to be calculated once.
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+  ## Return a matrix that is the inverse of 'x'
+  inverse <- x$get.inverse()
+  if (!is.null(inverse)) {
+    message("getting cached data")
+    return(inverse)
+  }
+  data <- x$get()
+  inverse <- solve(data, ...)
+  x$set.inverse(inverse)
+  inverse
 }