Implement makeCacheMatrix and cacheSolve functions

Author: iksemot

Diff for: cachematrix.R

@@ -1,15 +1,78 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
-
-makeCacheMatrix <- function(x = matrix()) {
-
-}
-
-
-## Write a short comment describing this function
-
-cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
-}
+## Below functions allows to create a cache-enabled version of matrix and
+## cache the matrix' inverse (result of solve function). This allows to cache
+## a time consuming operation. For more details refer to functions descriptions.
+##
+## Usage Example:
+## > cm <- makeCacheMatrix(matrix(1:4, ncol=2))
+##
+## > cm$get()
+##      [,1] [,2]
+## [1,]    1    3
+## [2,]    2    4
+##
+## > cacheSolve(cm)
+##      [,1] [,2]
+## [1,]   -2  1.5
+## [2,]    1 -0.5
+##
+## > cacheSolve(cm)
+## getting cached data....
+##      [,1] [,2]
+## [1,]   -2  1.5
+## [2,]    1 -0.5
+##
+## > cm$getSolve()
+##      [,1] [,2]
+## [1,]   -2  1.5
+## [2,]    1 -0.5
+
+makeCacheMatrix <- function(x = matrix()) {
+	# Creates cache-enabled matrix.
+	#
+	# Args:
+	#   x: a matrix object
+	#
+	# Returns:
+	#   An object with 4 functions:
+	#   - get() returns data
+	#   - set(y) changes data
+	#   - getSolve() returns matrix' inverse
+	#   - setSolve() sets the matrix' inverse
+	
+	s <- NULL
+	set <- function(y) {
+		x <<- y
+		s <<- NULL
+	}
+	get <- function() x
+	setSolve <- function(solve) s <<- solve
+	getSolve <- function() s
+	list(set      = set,
+		 get      = get,
+		 setSolve = setSolve,
+		 getSolve = getSolve)
+}
+
+cacheSolve <- function(x) {
+	# Caches the inverse of a matrix created with makeCacheMatrix function.
+	#
+	# Notes:
+	#  Function doesn't take /.../ argument as /solve/ shouldn't be passed
+	#  more than the data to inverse the matrix.
+	#
+	# Args:
+	#   x: matrix created with makeCacheMatrix function.
+	#
+	# Returns:
+	#  /x/ matrix' inverse
+	
+	s <- x$getSolve()
+	if(!is.null(s)) {
+		message("getting cached data....")
+		return(s)
+	}
+	data <- x$get()
+	s <- solve(data)
+	x$setSolve(s)
+	s
+}