Implemented makeCacheMatrix and cacheSolve.

Author: jaymitchell

cachematrix.R

@@ -1,15 +1,40 @@
-## Put comments here that give an overall description of what your
-## functions do
+## Contains a pair of functions to cache an inverse matrix. The value
+## from makeCacheMatrix should be the first parameter to cacheSolve.
 
-## Write a short comment describing this function
+## Creates a matrix structure whose inverse matrix can be cached.
+## The resulting list has the following structure:
+## - set: sets the original matrix to be solved.
+## - get: gets the original matrix.
+## - setinverse: sets the inverse matrix of the original matrix.
+## - getinverse: gets the inverse matrix of the original matrix.
 
 makeCacheMatrix <- function(x = matrix()) {
-
+        solved <- NULL
+        set <- function(y) {
+                x <<- y
+                solved <<- NULL
+        }
+        get <- function() x
+        setinverse <- function(inverse) solved <<- inverse
+        getinverse <- function() solved
+        list(set = set, get = get,
+             setinverse = setinverse,
+             getinverse = getinverse)
 }
 
 
-## Write a short comment describing this function
+## Returns the inverse of a matrix if it has been solved. Otherwise, it
+## will solve the inverse matrix and cache it for future use.
 
 cacheSolve <- function(x, ...) {
         ## Return a matrix that is the inverse of 'x'
+        i <- x$getinverse()
+        if(!is.null(i)) {
+                message("getting cached data")
+                return(i)
+        }
+        data <- x$get()
+        i <- solve(data, ...)
+        x$setinverse(i)
+        i
 }