Submission for programming assignment 2

charliefactory · charliefactory · commit bf4bd2ff5d7f · 2014-12-20T14:44:43.000-08:00
diff --git a/cachematrix.R b/cachematrix.R
@@ -1,15 +1,45 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
+## This file has two functions that compute the inverse of a given
+## square matrix. These two assume that the provided input is a 
+## invertible matrix
+##
+## Sample code using these functions to get matrix inverse:
+## > R = makeCacheMatrix(matrix(c(0,1,5,2,1,6,3,4,1),3,3))
+## > cacheSolve(R)
+##
 
+## makeCacheMatrix: This function creates a special "matrix" object 
+## that can cache its inverse.
 makeCacheMatrix <- function(x = matrix()) {
-
+        inverse <- NULL
+        set <- function(y) {
+                x <<- y
+                inverse <<- NULL
+        }
+        get <- function() x
+        setInverse <- function(solve) inverse <<- solve
+        getInverse <- function() inverse
+        list(set = set, get = get,
+             setInverse = setInverse,
+             getInverse = getInverse)
 }
 
 
-## Write a short comment describing this function
-
+## cacheSolve: This function computes the inverse of the 
+## special "matrix" returned by makeCacheMatrix function. 
+## If the inverse has already been calculated 
+## (and the matrix has not changed), 
+## then the cachesolve will retrieve the inverse from the cache.
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+        inverse = x$getInverse()
+        
+        ## Return cached inverse if it already has been computed & cached
+        if(!is.null(inverse)){
+                message("getting cached data")
+                return(inverse)
+        }
+        
+        data <- x$get()
+        inverse <- solve(data,...)
+        x$setInverse(inverse)
+        inverse 
 }
