## This two functions are used to save computing power needed to inverse

## matrices. It's done by calling cacheSolve() function on the output of

## a constructor function makeCacheMatrix(), eg:

#

# matrixX <- matrix(rnorm(16), 4,4,)

# y <- makeCacheMatrix(matrixX) #1. matrix is saved to and can be retrived later

# # by $get() method

# #2. A list of 4 elements is returned

# # (outputs of: get(), set(), getinverse(),

# # setinverse()).

# cacheSolve(y) # 1. when called for the first time calculate new

# # new inverse matrix using solve(matrixX) function

# # 2. when called another time instead of repeating

# # the same calculation for the same matrix, return saved

# # result

## stores matrix and inverse of a matrix after it's passed from cacheSolve()

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)

}

## First, check if the inverse matrix has already calculated,

## Then, return it or calculate and save with makeCacheMatrix(x)$setinverse(inv)

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

## Return a matrix that is the inverse of 'x'

inv <- x$getinverse()

if(!is.null(inv)) {

message("getting cached inverse matrix")

return(inv)

}

mat <- x$get()

inv <- solve(mat, ...)

x$setinverse(inv)

message("New calculated inverse matrix is:")

return(inv)

}