committing my work

marks · marks · commit 6ad21a48acc5 · 2016-10-02T12:26:50.000-05:00
diff --git a/cachematrix.R b/cachematrix.R
@@ -1,15 +1,38 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
+## This file contains code to create an object that is able to cache a matrix's inverse
 
+## This function creates a special matrix object that has  attributes to get and set both the matrix and its inverse
 makeCacheMatrix <- function(x = matrix()) {
-
+    inverse <- NULL
+    set <- function(y) {
+        x <<- y
+        inverse <<- NULL
+    }
+    get <- function() x
+    setInverse <- function(inverse) inverse <<- inverse
+    getInverse <- function() inverse
+    list(set = set, get = get,
+         setInverse = setInverse,
+         getInverse = getInverse)
 }
 
-
-## Write a short comment describing this function
-
+## This function returns the specified matrix's inverse from cache, if available, and computes and stores the inverse in cache if the cache is not available.
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+    inverse <- x$getInverse()
+    # if inverse is not null (it was in the cache), return it
+    if(!is.null(inverse)) {
+        message("getting inverse from cache")
+        return(inverse)
+    }
+    # otherwise, get the matrix's data, compute the inverse, and store it in cache
+    data <- x$get()
+    inverse <- solve(data, ...)
+    x$setInverse(inverse)
+    inverse # return the newly computed and stores inversesolv
 }
+
+
+## "Tests"
+# m <- matrix(c(0, 2, 1, 0), nrow = 2, ncol = 2, byrow = TRUE)
+# cm <- makeCacheMatrix(m)
+# cacheSolve(cm) # works!
+# cacheSolve(cm) == solve(m) # tells me cm$getInverse() has the same value as solve(m)
