[ESS] Starting intro to literate programming/ESS/Org mode?

[Kevin Zembower]

Hello, all,

I'd like to take the opportunity of taking Basic Statistics this
semester to learn the systems and structure of literate programming. I
would like to complete my homework assignments in a literate
programming document, that shows the data used as well as the results
created.

I'm somewhat familiar with a limited type of literate programming,
using Emacs/ESS, LaTeX, NoWeb and knitr. Here's an example of what I
can do already:
=================================
% To create the final PDF output document, in R do:
%     library(knitr)
%     knit2pdf("HW2.6.Rnw")

\documentclass{article}

\begin{document}

<<prelim, echo=FALSE>>=
library(tidyverse)
@

Question 1:
Predicted value:
<< Q1, echo=TRUE, include=TRUE>>=
Age <- 12
Hgt <- 24.2 +2.74*Age
Hgt
60 - Hgt
@
\end{document}
================================================

What I'd like to learn is the technique of using Org mode, and, I
think, RMarkdown to do literate programming without the overhead of
learning LaTeX.

Here's an example of what I couldn't get to work (this file is
HW2.6.org):
=============================================
<!-- Attempt to complete MATH 231 Basic Statistics homework using
Emacs, ESS and literate programming. -->

#+TITLE: MATH 231 HW 2.6
#+AUTHOR: Kevin Zembower

#+PROPERTY: header-args:R :session *R* :tangle HW2.6.R :comments both
:results raw :exports both :dir ~/Courses/TU_MATH231_BasicStatistics/HW

* Introduction
** Question 1
This is an example of a question and answer.

#+begin_src R 
  str(mtcars)
#+end_src

#+RESULTS:

#+begin_src R  :file a.png
  y <- rnorm(10)
  plot(x, y)
#+end_src
====================================

When I load this file into Emacs, the status bar shows "(Org PM)"
which, I think, indicates that it's in Org-mode as a major mode, and
PolyMode as minor. However, keystrokes that I thought would create
structures, such as "<s" creating the "#+begin_src R ... #+end_src"
template don't work.

Most importantly, I'm having trouble finding sources of information
that are up-to-date and accurate. I spent most of yesterday trying to
find a tutorial on literate programming/Emacs/ESS/Org mode/etc, but
most of the sources I found seemed to describe tools and plugins which
other sources claimed were out of date. I couldn't follow any of the
tutorials and get the results they described. For instance, in the
sample above, while the source block correctly executed in the R
buffer, the results never appeared below #+RESULTS, as I thought they
should.

My question is, what link or source would you suggest for me to study
and work on to try to learn the current best-practices for using
Emacs/ESS and R to do literate programming? 

Thank you for your advice and guidance. I appreciate your efforts to
help me.

-Kevin