My solution.

e-mu-pi · e-mu-pi · commit ee75f9ee9e24 · 2014-09-16T14:42:26.000-05:00
diff --git a/cachematrix.R b/cachematrix.R
@@ -1,15 +1,35 @@
-## Put comments here that give an overall description of what your
-## functions do
+## Define a cached matrix class that can cache 
+## the inverse.
 
-## Write a short comment describing this function
+## Construct a cached matrix from a matrix
 
 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
+## Compute inverse of a cached matrix. If already 
+## computed, cached version is used.
 
 cacheSolve <- function(x, ...) {
         ## Return a matrix that is the inverse of 'x'
+  inv <- x$getinverse()
+  if( !is.null(inv) ){
+    message("getting cached inverse")
+    return(inv)
+  }
+  data <- x$get()
+  inv <- solve(data,...)
+  x$setinverse(inv)
+  inv
 }
