Update cachematrix.R

susycote · susycote · commit abf76f7443b9 · 2014-08-23T12:09:39.000-06:00
Submission rdpeng#1
diff --git a/cachematrix.R b/cachematrix.R
@@ -1,15 +1,28 @@
-## Put comments here that give an overall description of what your
-## functions do
+## These functions take a matrix as input and calculate it's inverse. The inverse is cached so that it can be accessed later
 
-## Write a short comment describing this function
+## makeCacheMatrix takes a matrix as input and calculates the inverse. The inverse and matrix itself are outputs to a list. 
 
 makeCacheMatrix <- function(x = matrix()) {
-
+	inverseCache <- NULL
+	get <- function() {x}
+	setinverse <- function(solve)
+			{inverseCache <<- solve}
+	getinverse <- function() {inverseCache}
+	list(get = get , setinverse = setinverse , getinverse = getinverse)
 }
 
 
-## Write a short comment describing this function
+## cacheSolve returns the inverse of a matrix. It first checks to see if the inverse has already been calculated. If so, it returns the cached inverse. If not, it calculates the inverse and returns it, storing the inversion in the same object as makeCacheMatrix. 
 
+## Return a matrix that is the inverse of 'x'
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+	inverseCache <- x$getinverse
+	if(!is.null(inverseCache)){
+		message('getting cached matrix inversion')
+		return(inverseCache)
+	}
+	matrixdata <- x$get()
+	inverseCache <- solve(matrixdata)
+	x$setinverse(inverseCache)
+	inverseCache
 }
