diff --git a/cachematrix.R b/cachematrix.R index a50be65aa44..94dca87c287 100644 --- a/cachematrix.R +++ b/cachematrix.R @@ -1,15 +1,38 @@ -## Put comments here that give an overall description of what your -## functions do - -## Write a short comment describing this function +# The functions below provide a way to cache matrix inversions +# This function creates a special matrix which is really +# a list containing a function to +# 1. set the value of the matrix +# 2. get the value of the matrix +# 3. set the value of the inverse +# 4. get the value of the inverse 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 - +# The following function calculates the inverse of the special "matrix" +# created with makeCacheMatrix. +# However, it first checks for an already cached inverse and skips +# the computation if it finds one. cacheSolve <- function(x, ...) { - ## Return a matrix that is the inverse of 'x' + ## Return a matrix that is the inverse of 'x' + inv <- x$getinverse() + if(!is.null(inv)) { + message("getting cached data!") + return(inv) + } + data <- x$get() + inv <- solve(data, ...) + x$setinverse(inv) + inv }