Update cachematrix.R

Houdini · Houdini · commit 9416291f5eed · 2014-05-26T05:34:47.000+09:00
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
-
-## Write a short comment describing this function
+## Use example:
+## a <- makeCacheMatrix(matrix(1:4,2,2))
+## cacheSolve(a) # real computations
+## cacheSolve(a) # extracting from cache
 
+## Make a special cache object, vary much like a class.
+## Same as original assignment
 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
+## Same function as original, just use solve instead mean
 
 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  
 }
