Assignment solution and example code

Author: oyvindsk

cachematrix.R

@@ -1,15 +1,41 @@
-## Put comments here that give an overall description of what your
-## functions do
 
-## Write a short comment describing this function
+## This file is the solution to programming assignment 2 and contains 2 functions.
+
+## Make a list of functions that work on a captured varible to store a matrix and a cached version of the inverse of the same matrix. 
+## No computation in this funxtion, only getter & setter functions that work on the captured variable.
 
 makeCacheMatrix <- function(x = matrix()) {
 
+    ## Store the cached inverse matrix "inside" this closure
+    cache <- NULL
+    
+    ## Getter / setter functions to return
+    get         <- function()  x
+    getInverse  <- function()  cache
+    setInverse  <- function(m) cache <<- m 
+    
+    ## return a list of functions, like the example code
+    list(get = get, getInverse = getInverse, setInverse = setInverse)
 }
 
 
-## Write a short comment describing this function
+## Solve the inverse of a matrix, using the closue we created with makeCacheMatrix
+## If the cache is set return that. If not, solve() for matrix and return the result after setting the cache
 
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+    
+    inv <- x$getInverse() # # the varibale we will return after setting it to the correct matrix
+    
+    if(is.null(inv)){
+        # Nothing cached, solve and fill the cache
+        matrix <- x$get()
+        inv <- solve(matrix)
+        x$setInverse(inv)
+    } else {
+        # Got cached result, nothing to do
+        message("getting cached data")
+    }
+    
+    inv
+
 }

example.R

@@ -0,0 +1,28 @@
+
+## Use the example from the assignment
+
+makeVector <- function(x = numeric()) {
+    m <- NULL
+    set <- function(y) {
+        x <<- y
+        m <<- NULL
+    }
+    get <- function() x
+    setmean <- function(mean) m <<- mean
+    getmean <- function() m
+    list(set = set, get = get,
+         setmean = setmean,
+         getmean = getmean)
+}
+
+cachemean <- function(x, ...) {
+    m <- x$getmean()
+    if(!is.null(m)) {
+        message("getting cached data")
+        return(m)
+    }
+    data <- x$get()
+    m <- mean(data, ...)
+    x$setmean(m)
+    m
+}