From 309e3fab61447dfb7fa07789409ee3551dea9354 Mon Sep 17 00:00:00 2001
From: Rob Baker <rrbaker@gmail.com>
Date: Wed, 1 Jun 2016 00:18:19 -0400
Subject: [PATCH] homework

---
 cachematrix.R | 34 ++++++++++++++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..759e6af7493 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -4,12 +4,42 @@
 ## Write a short comment describing this function
 
 makeCacheMatrix <- function(x = matrix()) {
+    inv <- NULL
 
+    set <- function(y){
+        x <<- y
+        inv <<- NULL
+    }
+
+    get <- function() x
+    setinv <- function(solve) inv <<- solve
+    getinv <- function() inv
+    list(set = set, get = get, setinv = setinv, getinv = getinv)
 }
 
 
-## Write a short comment describing this function
+# This function delivers the inverted matrix from makeCacheMatrix,
+# first looking for a cached version and if not there
+# computing and returning the inversion.
 
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+    # Return an inverted matrix of the passed matrix.
+    inv <- x$getinv()
+
+    # Look for a cached version
+    if(!is.null(inv)) {
+        message("Aw yiss, a cached version.")
+        return(inv)
+    }
+    
+    # Otherwise invert the matrix.
+    data <- x$get()
+    inv <- solve(data, ...)
+    x$setinv(inv)
+    inv
 }
+
+# Test it out
+test <- makeCacheMatrix()
+test$set(matrix(c(1:4),2,2))
+cacheSolve(test)