From 483a2cb0c4939e46e4903ac052b6f8cd176932e1 Mon Sep 17 00:00:00 2001
From: Lawrence Lin <deduce@gmail.com>
Date: Sun, 27 Apr 2014 14:55:39 +0800
Subject: [PATCH 1/2] Complete the functions.

---
 cachematrix.R | 38 +++++++++++++++++++++++++++++---------
 1 file changed, 29 insertions(+), 9 deletions(-)

diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..414f6e64ccb 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,15 +1,35 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
-
+## funtcion makeCacheMatrix() creates a special "matrix" object that can cache its inverse.
 makeCacheMatrix <- function(x = matrix()) {
-
+    m <- NULL
+    set <- function(y) {
+        x <<- y
+        m <<- NULL
+    }
+    get <- function() x
+    setInverse <- function(solve) m <<- solve
+    getInverse <- function() m
+    list(set = set, get = get,
+        setInverse = setInverse,
+        getInverse = getInverse)
 }
 
+## cacheSolve() computes the inverse of the special "matrix" returned by makeCacheMatrix above.
+## If the inverse has already been calculated (and the matrix has not changed), then the cachesolve
+## should retrieve the inverse from the cache.
+cacheSolve <- function(x, ...) {
+    m <- x$getInverse()
 
-## Write a short comment describing this function
+    ## Return a matrix that is the inverse of 'x' if the inverse has already been calculated and cached. 
+    if(!is.null(m)) {
+        message("getting cached data")
+        return(m)
+    }
 
-cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+    ## Calculate the inverse of 'x' if the cached data doesn't exist.
+    data <- x$get()
+    m <- solve(data, ...)
+    x$setInverse(m)
+
+    ## Return a matrix that is the inverse of 'x'
+    m
 }

From b185518c6d9a5feb8fd5259c4cabd611731f1860 Mon Sep 17 00:00:00 2001
From: Lawrence Lin <deduce@gmail.com>
Date: Sun, 27 Apr 2014 15:01:45 +0800
Subject: [PATCH 2/2] Typo fixed, more comments added.

---
 cachematrix.R | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/cachematrix.R b/cachematrix.R
index 414f6e64ccb..8d4a5c643a6 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,4 +1,10 @@
-## funtcion makeCacheMatrix() creates a special "matrix" object that can cache its inverse.
+## function makeCacheMatrix() creates a special "matrix" object that can cache its inverse.
+## There are several functions:
+## 1. set the value of the matrix
+## 2. get the value of the matrix
+## 3. set the inverse of the matrix
+## 4. get the inverse of the matrix
+
 makeCacheMatrix <- function(x = matrix()) {
     m <- NULL
     set <- function(y) {
@@ -19,7 +25,7 @@ makeCacheMatrix <- function(x = matrix()) {
 cacheSolve <- function(x, ...) {
     m <- x$getInverse()
 
-    ## Return a matrix that is the inverse of 'x' if the inverse has already been calculated and cached. 
+    ## Return a matrix that is the inverse of 'x' if the inverse has already been calculated and cached.
     if(!is.null(m)) {
         message("getting cached data")
         return(m)