Commit rdpeng#1

Author: dzpiers

cachematrix.R

@@ -1,15 +1,42 @@
-## Put comments here that give an overall description of what your
-## functions do
+## ProgrammingAssignment2
 
-## Write a short comment describing this function
+## This function creates a "matrix" in that it makes a list containing functions
+## to set and get the value of the matrix and its inverse
 
 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
+## This function first checks to see if the inverse of the specified matrix has
+## been stored. If so it skips the calculation, otherwise it calculates the
+## inverse itself
 
 cacheSolve <- function(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
 }
+## Return a matrix that is the inverse of 'x'
+
+## Test for yourself here
+
+A <- matrix(c(1,2,3,4),2,2)
+A1 <- makeCacheMatrix(A)
+cacheSolve(A1) ## Run this line twice to get the message