init repo

Author: marpa

.gitignore

@@ -0,0 +1,4 @@
+.Rproj.user
+.Rhistory
+.RData
+ProgrammingAssignment2.Rproj

cachematrix.R

@@ -1,15 +1,42 @@
-## Put comments here that give an overall description of what your
-## functions do
+## These functions reduce the computation needed to find
+## the inverse of a matrix by caching the inverse the 1st
+## is it calculated
 
-## Write a short comment describing this function
+## cache the inverse of x and provide methods for
+## setting and getting that inverse
 
 makeCacheMatrix <- function(x = matrix()) {
-
+        i <- NULL
+        set <- function(y) {
+                x <<- y
+                i <<- NULL
+        }
+        get <- function() x
+        setinverse <- function(solve) i <<- solve
+        getinverse <- function() i
+        list(set = set, get = get,
+             setinverse = setinverse,
+             getinverse = getinverse)
 }
 
-
-## Write a short comment describing this function
+## get the inverse of x, using getinverse to get
+## it from cache or setinverse to cache it
 
 cacheSolve <- function(x, ...) {
+        i <- x$getinverse()
+        if(!is.null(i)) {
+                message("getting cached data")
+                return(i)
+        }
+        data <- x$get()
+        i <- solve(data, ...)
+        x$setinverse(i)
         ## Return a matrix that is the inverse of 'x'
+        message("getting data")
+        return(i)
 }
+
+## testing data
+
+y = matrix(c(1,2, 6,8), nrow=2, ncol=2)
+x <- makeCacheMatrix(y)