## cacheMatrix, provides two functions that compute the inverse of a matrix and cache it

# for future use. The first function makeCacheMatrix takes a matrix as a single argument.

# The matrix is assumed to be inversible. It returns a list of four helper functions to get & set a

# matrix, and to get and set its cached inverse

# The second function cacheSolve computes the inverse of a matrix and returns its value

# Sample code to test

# source("cacheMatrix.R")

# c=rbind(c(1, -1/4), c(-1/4, 1))

# a <- makeCacheMatrix(c)

# a$get()

# s <- cacheSolve(a)

# s

# a$set(s)

# a$get()

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

## is comprised of a list of four functions (set, get, setinverse, getinverse). get returns

## the current matrix, set is use to set the matrix to a new matrix, getinverse returns the

## cached copy of the inverse, setinverse sets the cache to the new value of the inverse

makeCacheMatrix <- function(x = matrix()) {

m <- NULL

get <- function() x

set <- function(y) {

x <<- y

m <<- NULL

}

setinverse <- function(inverse) m <<- inverse

getinverse <- function() m

list(get = get,

set = set,

setinverse = setinverse,

getinverse = getinverse)

}

## 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 cached copy

## is returned. Otherwise we assume the current matrix is inversible and use solve(X) to inverse the

## matrix and return the result

cacheSolve <- function(x, ...) {

m <- x$getinverse()

if(!is.null(m)) {

message("getting cached data")

return(m)

}

data <- x$get()

m <- solve(data)

x$setinverse(m)

m

}