1- # # Put comments here that give an overall description of what your
2- # # functions do
3-
4- # # Write a short comment describing this function
5-
6- makeCacheMatrix <- function (x = matrix ()) {
1+ # # makeCacheMatrix: This function creates a special 'matrix' object
2+ # # that can cache its inverse.
3+ # # cacheSolve: This function computes the inverse of the special 'matrix'
4+ # # returned by makeCacheMatrix above. If the inverse has already been
5+ # # calculated (and the matrix has not changed), then the cachesolve
6+ # # should retrieve the inverse from the cache.
7+ # # Computing the inverse of a square matrix can be done with the solve function in R.
8+ # # For example, if X is a square invertible matrix, then solve(X) returns its inverse.
79
10+ # # Function builds the psuedo-matrix object, which is really a list of functions to:
11+ # # 1. set the matrix value
12+ # # 2. get the matrix value
13+ # # 3. set the matrix inverse value
14+ # # 4. get the matrix inverse value
15+ makeCacheMatrix <- function (m = matrix ()) {
16+ m_inverse <- NULL
17+ set <- function (new_m ) {
18+ m <<- new_m
19+ m_inverse <<- NULL
20+ }
21+ get <- function () m
22+ setinv <- function (m_inv ) m_inverse <<- m_inv
23+ getinv <- function () m_inverse
24+ list (set = set , get = get ,
25+ setinv = setinv ,
26+ getinv = getinv )
827}
928
10-
11- # # Write a short comment describing this function
12-
29+ # # Calculates the inverse of the special "matrix" created with makeCacheMatrix()
30+ # # Tt first checks to see if the matrix inverse has already been calculated.
31+ # # If so, it gets the value from the cache and skips the computation.
32+ # # Otherwise, it calculates the data and sets the value in the cache
1333cacheSolve <- function (x , ... ) {
14- # # Return a matrix that is the inverse of 'x'
15- }
34+ # # Return a matrix that is the inverse of 'x' either via cache or computation
35+ inv <- x $ getinv()
36+ if (! is.null(inv )) {
37+ message(" getting cached data"
38+ return (inv )
39+ }
40+ data <- x $ get()
41+ c_inv <- solve(data , ... )
42+ x $ setinv(c_inv )
43+ c_inv
44+ }
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