initial draft

Author: kevinbluer

cachematrix.R

@@ -1,15 +1,58 @@
-## Put comments here that give an overall description of what your
-## functions do
 
-## Write a short comment describing this function
+
+## This function creates 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
+  
+  setmatrix <- function(matrix) m <<- matrix
+  getmatrix <- function() m
+  
+  list(set = set, get = get,
+       setmatrix = setmatrix,
+       getmatrix = getmatrix)
+  
 }
 
 
-## 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'
+  
+  ## Return a matrix that is the inverse of 'x'
+  
+  m <- x$getmatrix()
+  if(!is.null(m)) {
+    message("getting cached data")
+    return(m)
+  }
+  data <- x$get()
+  m <- solve(data, ...)
+  x$setmatrix(m)
+  m
+  
 }
+
+# steps to test
+
+# load makeCacheMatrix and cacheSolve 
+
+# m <- matrix(
+# c(3, 1, 5, 7),
+# nrow=2,
+# ncol=2,
+# byrow = TRUE)
+
+# mc <- makeCacheMatrix(m)
+
+# cacheSolve(mc)