Update cachematrix.R

cachematrix.R

@@ -1,15 +1,34 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
+#makeCacheMatrix: This function creates a special "matrix" object that can cache its inverse.
+#cacheSolve: This function computes the inverse of the special "matrix" returned by makeCacheMatrix above. 
+#If the inverse has already been calculated (and the matrix has not changed), then cacheSolve should retrieve the inverse from the cache.
 
+## Write a cache function
 makeCacheMatrix <- function(x = matrix()) {
-
+    inverse <- NULL
+    set <- function(y) {
+        x <<- y
+        inverse <<- NULL
+    }
+    get <- function() x
+    setsolve <- function(solve) inverse <<- solve
+    getsolve <- function() inverse
+    list(set = set, get = get,
+         setsolve = setsolve,
+         getsolve = getsolve)
 }
 
 
-## Write a short comment describing this function
-
+## get an inverse matrix from cache if there's one, or make a new one
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+    ## Return a matrix that is the inverse of 'x'
+    x.inverse <- x$getsolve()
+    if(!is.null(x.inverse)) {
+        message("getting cached data")
+        return(x.inverse)
+    }
+    data <- x$get()
+    x.inverse <- solve(data, ...)
+    x$setsolve(x.inverse)
+    x.inverse
+
 }