Programming Assignment 2: Lexical Scoping

Assignment: Caching the Inverse of a Matrix Part of R Programming course, by Coursera (https://www.coursera.org/learn/r-programming/home/info)

Creating the cache

Starting from a new matrix or having it passed to the function, 'makeCacheMatrix' will return a list with four functions.

This four functions enables the cache maintenance. Two of them are meant to be used internally, and two externally.

The external functions, setsolve and getsolve will respectivelly set and get the data to be managed

makeCacheMatrix <- function(x = matrix()) {
  m <- NULL
  
  set <- function(y) {
    x <<- y
    m <<- NULL
  }
  
  get <- function() x
  
  setinverted <- function(val) m <<- val
  
  getinverted <- function() m
  
  list(
      set = set,
      get = get,
      setinverted = setinverted,
      getinverted = getinverted)
}

Usage:

my_matrix <- makeCacheMatrix(matrix(c(10, 3, 2, 2), nrow=2, ncol=2))

Using cache to increase performance

Given an previously created cache (see makeCacheMatrix above), cacheSolve will return an inverted given matrix. Only the last cached object will be returned. If the matrix changes, makeCacheMatrix must be called again

cacheSolve <- function(x, ...) {
  inverted <- x$getinverted()
  
  if(!is.null(inverted)) {
    message("getting cached data")
    return(inverted)
  }
  
  data <- x$get()
  
  inverted <- solve(data)
  x$setinverted(inverted)
  
  inverted
}

Usage:

cacheSolve(my_matrix)

Author

Marcos Braga Choma, 2017-06-10