From 95d6b3fb59776ca12f00d997580d3454a35d0107 Mon Sep 17 00:00:00 2001
From: bobl49 <blindenberg@tiaa-cref.org>
Date: Sun, 26 Apr 2015 21:36:57 -0400
Subject: [PATCH] Update cachematrix.R

---
 cachematrix.R | 41 +++++++++++++++++++++++++++++++++++------
 1 file changed, 35 insertions(+), 6 deletions(-)

diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..ceee24f54ae 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,15 +1,44 @@
-## Put comments here that give an overall description of what your
-## functions do
+## These functions make an object which is a cacheable form of 
+## a matrix and its inverse. To use it, first call
+## invX<-makeCacheMatrix(x)
+## invX$set(x)
+## Then to retrieve the inverse, call
+## cacheSolve(xInv)
+## to see x call
+## inv$get()
 
-## Write a short comment describing this function
+## makeCacheMatrix creates a cacheable form of the matrix x and
+## its inverse m
 
 makeCacheMatrix <- function(x = matrix()) {
-
+  m <- NULL
+  set <- function(y) {
+    x <<- y
+    m <<- NULL
+  }
+  get <- function() x
+  setInverse <- function(inverse) m <<- inverse
+  getInverse <- function() m
+  list(set = set, get = get,
+       setInverse = setInverse,
+       getInverse = getInverse)
 }
 
 
-## Write a short comment describing this function
+## cacheSolve takes as arguments an object x 
+##and other ... arguments for the solve() functioncreated by the makeCacheMatrix
+## function and returns its inverse, either from cache or computed
+## directly. 
 
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+  ## Return a matrix that is the inverse of 'x'
+  m <- x$getInverse()
+  if(!is.null(m)) {
+    message("getting cached data")
+    return(m)
+  }
+  data <- x$get()
+  m <- solve(data, ...)
+  x$setInverse(m)
+  m
 }