Assignment 2

Author: wal

cachematrix.R

@@ -1,15 +1,41 @@
-## Put comments here that give an overall description of what your
-## functions do
+# Create a CacheMatrix, a special Matrix object that can cache its inverse (available by calling getInverse)
+makeCacheMatrix <- function(x = matrix()) {
 
-## Write a short comment describing this function
+    # Initialize inverse as null (will be calculated on demand)
+    inverse <- NULL
+    
+    # A set function to set the Matrix and reset the cached inverse
+    set <- function(y) {
+        x <<- y
+        inverse <<- NULL
+    }
 
-makeCacheMatrix <- function(x = matrix()) {
+    # Get function to retrieve the Matrix
+    get <- function() x
 
-}
+    # Functions to set and get the cached inverse
+    setInverse <- function(solve) inverse <<- solve
+    getInverse <- function() inverse
 
+    # Return list of the wrapped functions of the matrix
+    list(set = set, get = get, setInverse = setInverse, getInverse = getInverse)
+}
 
-## Write a short comment describing this function
 
+# Check if the inverse has already been calculated for this matrix and return it if so, otherwise calculate and cache the inversex
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+
+    # check if the inverse has been cached already
+    inverse <- x$getInverse()
+    
+    if(!is.null(inverse)) {
+        message("Using Cached inverse")
+        # Use the cached inverse
+        return(inverse)
+    }
+
+    # Inverse not cached, calculate and cache it
+    inverse <- solve(x$get(),...)
+    x$setInverse(inverse)
+    inverse    
 }

test.R

@@ -0,0 +1,10 @@
+source("cachematrix.R")
+
+a <- makeCacheMatrix(matrix(1:4,2))
+a$get()
+a$getInverse()
+a$set(matrix(5:8,2))
+a$get()
+cacheSolve(a)
+cacheSolve(a)
+a$getInverse()