## Put comments here that give an overall description of what your

## functions do

## Write a short comment describing this function

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

mat_inv <- NULL

if (ncol(x) == nrow(x)){

mat_inv <<- solve(x)

}

else {

message("Not a square matrix!")

return(x)

}

}

## Write a short comment describing this function

## The cacheSolve function will first check if the inverse of the input matrix exists,

## If not, it will call makeCheMatrix to calculate the inverse.

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

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

if (!is.null(mat_inv)){

message("getting cached data...")

return(mat_inv)

}

else{

makeCacheMatrix

}

}