add comments

Author: clawtros

cachematrix.R

@@ -1,30 +1,29 @@
-  ## Put comments here that give an overall description of what your
-## functions do
+## cachematrix: Functions to cache matrix inversion
 
-## Write a short comment describing this function
+## makeCacheMatrix sets up the scope for storing cache
 
 makeCacheMatrix <- function(x = matrix()) {
-  m <- NULL
-  set <- function(y) {
+  m <- NULL # initialize cache to NULL
+  set <- function(y) { # changing value invalidates cache
     x <<- y
     m <<- NULL
   }
-  get <- function() x
-  setinverse <- function(inverse) m <<- inverse
-  getinverse <- function() m
+  get <- function() x # return original matrix
+  setinverse <- function(inverse) m <<- inverse # set cache value to supplied value
+  getinverse <- function() m 
   list(set = set, get = get, setinverse=setinverse, getinverse=getinverse)
 }
 
-
-## Write a short comment describing this function
+## cacheSolve takes the list generated by makeCacheMatrix and either populates its cache
+## or returns the cached value
 
 cacheSolve <- function(x, ...) {
-  m <- x$getinverse()
+  m <- x$getinverse() # returns NULL if not yet cached
   if (!is.null(m)) {
-    message('cached inverse')
+    message('cached inverse') # report that returned value is from cache
     return(m)
   }
-  m <- solve(x$get())
+  m <- solve(x$get()) # uses solve to get inverse of x
   x$setinverse(m)
   m
 }