## Programming Assignment 2: Lexical Scoping. Caching the inverse of a

## matrix: functions that calculate the inverse of a matrix, in case

## it's not calculated previously.

## makeCacheMatrix creates a list that sets and gets the values of a matrix

## and its inverse

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

# initialize the inverse

i<<- NULL

# function to set the value of the matrix

set<- function(y){

y<<- x

}

# function to get the value of the matrix

get <- function() x

# function to set the function that calculates the inverse of a matrix

setinverse<- function(solve) i<<- solve

# function to get the value of the inverse

getinverse<- function() i

# list containing the previous values

list(set= set, get= get, setinverse= setinverse, getinverse= getinverse)

}

## cacheSolve calculates the inverse of the matrix set in the makeCacheMatrix

## function. It first checks if the inverse has already been calculated. In

## that case, gets the inverse from the cache.

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

# assign the value of the inverse searching in the getinverse() function

# calculated above

mi<<- x$getinverse()

# checking if the value already exists

if(!is.null(mi)) {

message("getting cached inverse")

return(mi) # return the previously calculated inverse

}

# composing the instruction to calculate the inverse

m<- x$get()

mi <- solve(m, ...)

# setting the new value of the inverse

x$setinverse(mi)

# returns the inverse

mi

}