Add matrix caching and solving code

Author: ryanblak

cachematrix.R

@@ -1,15 +1,57 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
-
-makeCacheMatrix <- function(x = matrix()) {
+# An instance of makeCacheMatrix can be initialised by passing a 
+# square matrix as an argument. The created instance can then be 
+# passed to cacheSolve, which will invert the matrix, cache and 
+# return  the result. Subsequent calls to cacheSolve with the 
+# same makeCacheMatrix instance will return the cached result 
+# and not invert the matrix again.
 
+# Allows caching of a matrix and its inverse value
+makeCacheMatrix <- function(matrix = matrix()) {
+  inverseMatrix <- NULL
+  
+  # Caches a matrix and clears the inverse cache
+  set <- function(newMatrix) {
+    matrix <<- newMatrix
+    inverseMatrix <<- NULL
+  }
+  
+  # Gets the original unsolved matrix
+  get <- function() matrix
+  
+  # Caches a solved matrix
+  setInverse <- function(inverse) inverseMatrix <<- inverse
+  
+  # Gets the solved matrix
+  getInverse <- function() inverseMatrix
+  
+  list(
+    set = set,
+    get = get,
+    setInverse = setInverse,
+    getInverse = getInverse
+  )
 }
 
 
-## Write a short comment describing this function
-
-cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+# Takes an initialised instance of makeCacheMatrix 
+# and solves or accesses the cached matrix within it
+cacheSolve <- function(matrixCacher, ...) {
+  inverseMatrix <- matrixCacher$getInverse()
+  
+  # Check if the cached original matrix has been solved already
+  if(!is.null(inverseMatrix)) {
+    return(inverseMatrix)
+  }
+  
+  # Get the original matrix
+  matrix <- matrixCacher$get()
+  
+  # Solve the original matrix
+  inverseMatrix <- solve(matrix)
+  
+  # Store the newly solved matrix
+  matrixCacher$setInverse(inverseMatrix)
+  
+  # Return the newly solved matrix
+  inverseMatrix
 }