ex2

Author: Sebastian Bassi

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
+
+## This function returns a list with 4 functions, set, get, setinv and getinv.
 
 makeCacheMatrix <- function(x = matrix()) {
+    m <- NULL
+    set <- function(y) {
+      x <<- y
+      m <<- NULL
+    }
+    get <- function() x
+    setinv <- function(inv) m <<- inv
+    getinv <- function() m
+    list(set = set, get = get,
+         setinv = setinv,
+         getinv = getinv)
 
 }
 
 
-## Write a short comment describing this function
-
+## this function, given the object produced by makeCacheMatrix, returns the inverse of a matrix
 cacheSolve <- function(x, ...) {
         ## Return a matrix that is the inverse of 'x'
+        m <- x$getinv()
+        if(!is.null(m)) {
+          message("getting cached data")
+          return(m)
+        }
+        data <- x$get()
+        m <- solve(data, ...)
+        x$setinv(m)
+        m
+
+
 }