Update cachematrix.R

Author: minhaz7

cachematrix.R

@@ -1,16 +1,52 @@
-## Put comments here that give an overall description of what your
-## functions do
+##Caching the Inverse of a Matrix
 
-## Write a short comment describing this function
+######Example of using the function##########
+#x<-matrix(1:4,2,2) #Original Matrix creation
+#xin<-makeCacheMatrix(x) #Creates a special "Matrix" xin returns  list of 4 functions
+#xin$get() #Return the original Matrix
+#cacheSolve(xin) #Compute and return the inverse of the original matrix
+#cacheSolve(xin) #Inverse already computed; show the message "getting cached data" and return the cached inverse matrix
 
+##In this example we use the <<- operator which assign a value to an object in an environment that is different from the current environment. 
+##Below are two functions that are used to create a special object that stores a numeric Matrix and cache's its inverse
 
-makeCacheMatrix <- function(x = matrix()) {
+##The first function, makeCacheMatrix creates a special "Matrix", which is really a list containing a function to
+##1) set the value of the matrix
+##2) get the value of the matrix
+##3) set the value of the inverse of the matrix
+##4) get the value of the inverse of the matrix
 
+makeCacheMatrix <- function(x = matrix()) {
+  myinv <- NULL# myinv object will store the cached inverse of the matrix
+  set <- function(y) { #Set the original Matrix
+    x <<- y
+    myinv <<- NULL
+  }
+  get <- function() x #Get the original Matrix
+  setinvrse <- function(invrse) myinv <<- invrse #Set the inverse Matrix
+  getinvrse <- function() myinv #Get the inverse Matrix
+  #Return the list containing the functions
+  list(set = set, get = get,setinvrse = setinvrse,getinvrse = getinvrse)    
 }
 
 
-## Write a short comment describing this function
+##The following function, cacheSolve, calculates the inverse of the special "Matrix" created with the above function. 
+##However, it first checks to see if the inverse has already been calculated. If so, it gets the inverse from the cache and skips the computation. 
+##Otherwise, it calculates the inverse of the Matrix and sets the value of the inverse in the cache via the setinvrse function.
 
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+  ## Return a matrix that is the inverse of 'x'
+  myinv <- x$getinvrse()
+  ##Checks to see if the inverse has already been calculated, if yes, return it
+  if(!is.null(myinv)) {
+    message("getting cached data")
+    return(myinv)
+  }
+  ##It calculates the inverse of the Matrix
+  data <- x$get()
+  myinv <- solve(data, ...)
+  ##Cache the inverse matrix
+  x$setinvrse(myinv)
+  ##Return the computed inverse matrix
+  myinv
 }