cachematrix.R

## makeCacheMatrix allows a get/set for matrix creation/retrieval

makeCacheMatrix <- function(x = matrix()) {
  
## matrix inverse placeholder, default value NULL  
  m <- NULL
  
##  Allows passing a new matrix to be created and re-sets matrix-inverse placeholder to NULL
  set <- function(y) {
    x <<- y
    m <<- NULL
  }

## gets the matrix inverse
  get <- function() x

## solves matrix/creates inverse and caches matrix inverse
  setmatrix <- function(solve) m <<- solve
## retrieves cached matrix inverse value
  getmatrix <- function() m
  
## returns value of function makeCacheMatrix
  list(set = set, get = get,
       setmatrix = setmatrix,
       getmatrix = getmatrix)

}


## creates an inverse of a matrix and caches, or retrieves it from cache if inverse has already been created

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

    m <- x$getmatrix()
    
##retrieves cached matrix inverse, if one exists    
    if(!is.null(m)) {
      message("getting cached data")
      return(m)
    }
    
## if no cached matrix inverse exists, creates the inverse and returns the matrix inverse.
    matrix <- x$get()
    m <- solve(matrix, ...)
    x$setmatrix(m)
    
## Return a matrix that is the inverse of 'x'
    m
}