initial version

Author: babyman

cachematrix.R

@@ -1,15 +1,50 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
-
-makeCacheMatrix <- function(x = matrix()) {
+## A pair of functions that combined can create an object wrapping a square
+## matrix that can cache its inverse to avoid the expense of this operation
+## executing more than once.
 
+## 'matrix_val' is a square matrix to be contained in the cache enabled object.
+##
+## Return an object that contains the input martix_val with the ability to
+## cache its inverse.
+##
+makeCacheMatrix <- function(matrix_val = matrix()) {
+  inverse_val <- NULL
+  set <- function(new_matrix) {
+    matrix_val <<- new_matrix
+    inverse_val <<- NULL
+  }
+  get <- function() {
+    matrix_val
+  }
+  setInverse <- function(updated) {
+    inverse_val <<- updated
+  }
+  getInverse <- function() {
+    inverse_val
+  }
+  list(set = set,
+    get = get,
+    setInverse = setInverse,
+    getInverse = getInverse)
 }
 
 
-## Write a short comment describing this function
-
+## 'x' the cache matrix object created by a call to makeCacheMatrix.
+## '...' any optional arguments that should be passed to the call to solve()
+##        used to invert the contained matrix.
+##
+## Return the inverted matrix value, this will be calculated on the first call
+## but the result will be stored in the matrix object for later use.
+##
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+  ## Return a matrix that is the inverse of 'x'
+  m <- x$getInverse()
+  if(is.null(m)) {
+    data <- x$get()
+    m <- solve(data, ...)
+    x$setInverse(m)
+  } else {
+    message("getting cached data")
+  }
+  m
 }