Solve prog. assignment 2

astangl · astangl · commit 022c2efe7c3d · 2015-08-16T16:25:29.000-05:00
diff --git a/cachematrix.R b/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
+## Pair of function that compute/cache the inverse of a matrix.
 
+## This function creates a special "matrix" object that can cache its inverse.
 makeCacheMatrix <- function(x = matrix()) {
+	s <- NULL
+	setMatrix <- function(y) {
+		x <<- y
+		s <<- NULL
+	}
+	getMatrix <- function() x
+	setSolve <- function(sol) s <<- sol
+	getSolve <- function() s
+	list(setMatrix = setMatrix, getMatrix = getMatrix,
+	     setSolve = setSolve, getSolve = getSolve)
 
 }
 
 
-## Write a short comment describing this function
-
+## 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.
 cacheSolve <- function(x, ...) {
         ## Return a matrix that is the inverse of 'x'
+	s <- x$getSolve()
+	if (!is.null(s)) {
+		message("getting cached data")
+		return(s)
+	}
+	data <- x$getMatrix()
+	s <- solve(data, ...)
+	x$setSolve(s)
+	s
 }
