R Programming Assignment 2 completed

opcode · opcode · commit 075b63a8dd0b · 2014-12-20T21:40:07.000+01:00
diff --git a/cachematrix.R b/cachematrix.R
@@ -1,15 +1,46 @@
-## Put comments here that give an overall description of what your
-## functions do
+##
+## R Programming, Assignment 2
+## Uses lexical scoping to create and cache the inverted matrix of a given matrix.
+##
 
-## Write a short comment describing this function
+# these lines are just for testing...
+#rm(list=ls())
+#setwd("~/Personal/Coursera/RProgramming/Labs/ProgrammingAssignment2");
+#getwd()
 
-makeCacheMatrix <- function(x = matrix()) {
 
+## makeCacheMatrix(x)
+## x is a matrix
+## returns a list of functions to manipulate x:
+## set(), get(), setinverse(), and getinverse()
+makeCacheMatrix <- function(x = matrix()) {
+    invm <- NULL
+    set <- function(y) {
+        x <<- y
+        invm <<- NULL
+    }
+    get <- function() x
+    setinverse <- function(m) invm <<- m
+    getinverse <- function() invm
+    list(set = set, get = get,
+         setinverse = setinverse,
+         getinverse = getinverse)
 }
 
 
-## Write a short comment describing this function
-
+## Return a matrix that is the inverse of 'x' (created by makeCacheMatrix)
+## and caches it in the object x
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+    invm <- x$getinverse()
+
+    if(!is.null(invm)) {
+        message("getting cached data")
+        return(invm)
+    }
+
+    data <- x$get()
+    invm <- solve(data, ...)
+    x$setinverse(invm)
+    invm
 }
+
diff --git a/cachevector.R b/cachevector.R
@@ -0,0 +1,25 @@
+    makeVector <- function(x = numeric()) {
+            m <- NULL
+            set <- function(y) {
+                    x <<- y
+                    m <<- NULL
+            }
+            get <- function() x
+            setmean <- function(mean) m <<- mean
+            getmean <- function() m
+            list(set = set, get = get,
+                 setmean = setmean,
+                 getmean = getmean)
+    }
+
+    cachemean <- function(x, ...) {
+            m <- x$getmean()
+            if(!is.null(m)) {
+                    message("getting cached data")
+                    return(m)
+            }
+            data <- x$get()
+            m <- mean(data, ...)
+            x$setmean(m)
+            m
+    }
