diff --git a/cachematrix.R b/cachematrix.R index a50be65aa44..cd22d6376ce 100644 --- a/cachematrix.R +++ b/cachematrix.R @@ -1,15 +1,32 @@ -## Put comments here that give an overall description of what your -## functions do - -## Write a short comment describing this function +# Matrix inversion is usually a costly computation and their may be some benefit +# to caching the inverse of a matrix rather than compute it repeatedly makeCacheMatrix <- function(x = matrix()) { - + # This function creates a special "matrix" object that can cache its inverse. + i <- NULL + set <- function(y) { + x <<- y + m <<- NULL + } + get <- function() x + setinverse <- function(inverse) i <<- inverse + getinverse <- function() i + list(set = set, get = get, setinverse = setinverse, getinverse = getinverse) } - -## Write a short comment describing this function - cacheSolve <- function(x, ...) { - ## Return a matrix that is the inverse of 'x' + # This function computes the inverse of the special "matrix" returned by + # makeCacheMatrix above. If the inverse has already been calculated (and the + # matrix has not changed), then the cachesolve should retrieve the inverse from + # the cache. + i <- x$getinverse() + if (!is.null(i)) { + message("gettting cached data") + return(i) + } + + data <- x$get() + i <- solve(data, ...) + x$setinverse(i) + i }