Update cachematrix.R

DavidHum · DavidHum · commit 57c51233ad91 · 2014-06-05T20:55:04.000-04:00
diff --git a/cachematrix.R b/cachematrix.R
@@ -1,15 +1,36 @@
-## Put comments here that give an overall description of what your
-## functions do
+## These function are used to make a matrix object that can cache its inverse
+## and return the cached inverse of that matrix
 
-## Write a short comment describing this function
+## makeCacheMatrix makes a special matrix object that can cache its inverse 
 
 makeCacheMatrix <- function(x = matrix()) {
-
+    m <- NULL
+    set <- function(y) {
+        x <<- y
+        m <<- NULL
+    }
+    get <- function() x
+    setInv <- function(solve) m <<- solve
+    getInv <- function() m
+    list(set = set, get = get,
+         setInv = setInv,
+         getInv = getInv)
 }
 
 
-## Write a short comment describing this function
+## cacheSolve then computes the inverse of the special matrix returnet by the
+## function makeCacheMatrix.
+## If the inverse has alredy been calculated and the matrix is the same
+## then cacheSolve should retrieve the inverse from the cache
 
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+    m <- x$getInv()
+    if(!is.null(m)) {
+        message("getting cached data")
+        return(m)
+    }
+    data <- x$get()
+    m <- solve(data, ...)
+    x$setInv(m)
+    m
 }
