Implemented makeCacheMatrix and cacheSolve

Author: dk920029

cachematrix.R

@@ -1,15 +1,34 @@
-## Put comments here that give an overall description of what your
-## functions do
+## Put comments here that give an overall description of what your functions do
+## These functions create a special "matrix" object that can cache its inverse.
 
 ## Write a short comment describing this function
-
+## This function creates a special "matrix" object that can cache its inverse.
 makeCacheMatrix <- function(x = matrix()) {
-
+  inv <- NULL
+  set <- function(y) {
+    x <<- y
+    inv <<- NULL
+  }
+  get <- function() x
+  setinverse <- function(inverse) inv <<- inverse
+  getinverse <- function() inv
+  list(set = set, get = get,
+       setinverse = setinverse,
+       getinverse = getinverse)
 }
 
-
 ## Write a short comment describing this function
-
+## This function 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 cacheSolve should retrieve the inverse from the cache.
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+  inv <- x$getinverse()
+  if (!is.null(inv)) {
+    message("getting cached data")
+    return(inv)
+  }
+  mat <- x$get()
+  inv <- solve(mat, ...)
+  x$setinverse(inv)
+  inv
 }