Solved assignment

Author: DorianStrasser

cachematrix.R

@@ -1,15 +1,58 @@
-## Put comments here that give an overall description of what your
-## functions do
+## cacheSolve and makeCacheMatrix are ment to speed up matrix calculation.
+## If the inverse of a matrix is allready calculated, it returns the cached value insted recalculating it.
 
-## Write a short comment describing this function
+## makeCacheMatrix creates a special matrix, which can store (set) and return (get) a matrix, but alos store (setinverse)
+## return (getinverse) its inverse matrix.
+##
+## makeCacheMatrix expects a matrix as argument.
 
 makeCacheMatrix <- function(x = matrix()) {
-
+  ## Initialize inverse as empty
+  i <- NULL
+  
+  ## set function takes a new matrix and delets the inverse
+  set <- function(y) {
+    x <<- y
+    i <<- NULL
+  }
+  
+  ## get function returns the matrix itself
+  get <- function() x
+  
+  ## setinverse sets the value of the inverse matrix
+  setinverse <- function(inverse) i <<- inverse
+  
+  ## getinverse returns the value of the inverse matrix
+  getinverse <- function() i
+  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'
+
+## cacheSolve alows to calculate the inverse of matrix faster by utilizingt a CacheMatrix (see makeCacheMatrix).
+## If the inverse of a matrix is allready calculated, it returns the cached value insted recalculating it.
+##
+## cacheSolve expects a matrix created by makeCacheMatrix as argument.
+
+cacheSolve <- function(x) {
+  ## Gets the saved inverse matrix
+  i <- x$getinverse()
+  
+  ## If the inverse is not NULL (which means: allready calculated) the value is returned
+  if(!is.null(i)) {
+    message("getting cached data")
+    return(i)
+  }
+  
+  ## Else: Get the matrix and calculate the inverse
+  data <- x$get()
+  i <- solve(data)
+  
+  ## Save the calculated value to cache an return the value
+  x$setinverse(i)
+  i  
 }