cachematrix.R

## This R script saves costly computation by storing the matrix inverse in the cache
## rather than compute it repeatedly 

## This function creates a special "matrix" object that can cache its inverse.

makeCacheMatrix <- function(x = matrix()) {
  i <- NULL
  set <- function(y) {
    x <<- y
    i <<- NULL
  }
  get <- function() x
  setinv <- function(solve) i <<- solve(x)
  getinv <- function() i
  list(set = set, get = get,
       setinv = setinv,
       getinv = getinv)
}


## This function computes the inverse of the special "matrix" returned 
## by makeCacheMatrix above. If the inverse has already been it retrieves it from cache

cacheSolve <- function(x, ...) {
  i <- x$getinv()
  if(is.matrix(i)) {
    message("getting cached data")
    return(i)
  }
  data <- x$get()
  i <- solve(data, ...)
  x$setinv(i)
  i
}