Update function and add comments for programming assignment 2

Author: dazari

cachematrix.R

@@ -1,15 +1,54 @@
-## Put comments here that give an overall description of what your
-## functions do
+## These functions are to speed up the process of inversing a matrix. This is
+## done by creating a special object to "cache" the matrix. The function makeCacheMatrix
+## must be run first for this assignment to create that special object. If the 
+## original matrix is changed, the makeCacheMatrix *must* be run again to 
+## accurately contain the inverse.
 
-## Write a short comment describing this function
+## This function assumes the given matrix will always be inversible.
 
+## This function creates a special "matrix" object that can cache its inverse.
 makeCacheMatrix <- function(x = matrix()) {
-
+  m <- NULL
+  ## matrix is cleared to create new special "matrix" object and setting matrix
+  set <- function(y) {
+    x <<- y
+    m <<- NULL
+  }
+  get <- function() x
+  
+  ## set the inverse of the matrix by rebinding
+  ## setmatrix in the parent of the current environment.
+  setmatrix <- function(solve) m <<- solve
+  getmatrix <- function() m
+  
+  ## create list for all functions
+  list(set = set, get = get,
+       setmatrix = setmatrix,
+       getmatrix = getmatrix)
 }
 
 
-## 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'
+        ## gets the matrix from cache if it exists
+        m <- x$getmatrix()
+      
+        ## check if matrix exists in special object cache
+        if(!is.null(m)) {
+          message("getting cached data")
+          ## Return a matrix that is the inverse of 'x' that was stored in
+          ## "special matrix" object when it was created
+          return(m)
+        }
+        ## the inverse matrix was not previously stored so we need to set it
+        data <- x$get()
+        ## compute the inverse of the special matrix with given data
+        m <- solve(data, ...)
+        ## set new m
+        x$setmatrix(m)
+        ## output the new m value
+        m
 }