TOPIC: MAN PAGE
Some books and other forms of documentation on R
11th September 2021The thrust of an exhortation from a computing handbook publisher comes to mind here: don't just look things up on Google, read a book so you really understand what you are doing. A form of words like that was used to sell an eBook on GitHub, but the same sentiment applies to R or any other computing language. While using a search engine will get you going or add to existing knowledge, only a book or a training course will help to embed real competence.
In the case of R, there is a myriad of blogs out there that can be consulted, as well as function and package documentation on RDocumentation or rrdr.io. For the former, R-bloggers or R Weekly can make good places to start, while ones like Stats and R, Statistics Globe, STHDA, PSI's VIS-SIG and anything from Posit (including their main blog as well as their AI one) can be worth consulting. Additionally, there is also RStudio Education and the NHS-R Community, which also have a GitHub repository together with a YouTube channel. Many packages have dedicated websites as well, so there is no lack of documentation with all of these, so here is a selection:
To come to the real subject of this post, R is unusual in that books that you can buy also have companion websites that contain the same content with the same structure. Whatever funds this approach (and some appear to be supported by RStudio itself by the looks of things), there certainly are many books available freely online in HTML as you will see from the list below, while a few do not have a print counterpart as far as I know:
R Programming for Data Science
R Markdown: The Definitive Guide
bookdown: Authoring Books and Technical Documents with R Markdown
blogdown: Creating Websites with R Markdown
pagedown: Create Paged HTML Documents for Printing from R Markdown
Dynamic Documents with R and knitr
Engineering Production-Grade Shiny Apps
Outstanding User Interfaces with Shiny
Happy Git and GitHub for the useR
Outstanding User Interfaces with Shiny
Engineering Production-Grade Shiny Apps
Many of the above have counterparts published by O'Reilly or Chapman & Hall, to name the two publishers that I have found so far. Aside from sharing these with you, there is also the personal motivation of having the collection of links somewhere so I can close tabs in my Firefox session. There are other web articles open in other tabs that I need to retain and share, but these will need to do for now, and I hope that you find them as useful as I do.
Reloading .bashrc within a BASH terminal session
3rd July 2016BASH is a command-line interpreter that is commonly used by Linux and UNIX operating systems. Chances are that you will find yourself in a BASH session if you start up a terminal emulator in many of these, though there are others like KSH and SSH too.
BASH comes with its own configuration files and one of these is located in your own home directory, .bashrc. Among other things, it can become a place to store command shortcuts or aliases. Here is an example:
alias us='sudo apt-get update && sudo apt-get upgrade'
Such a definition needs there to be no spaces around the equals sign, and the actual command to be declared in single quotes. Doing anything other than this will not work, as I have found. Also, there are times when you want to update or add one of these and use it without shutting down a terminal emulator and restarting it.
To reload the .bashrc file to use the updates contained in there, one of the following commands can be issued:
source ~/.bashrc
. ~/.bashrc
Both will read the file and execute its contents so you get those updates made available so you can continue what you are doing. There appears to be a tendency for this kind of thing in the world of Linux and UNIX because it also applies to remounting drives after a change to /etc/fstab and restarting system services like Apache, MySQL or Nginx. The command for the former is below:
sudo mount -a
Often, the means for applying the sorts of in-situ changes that you make are simple ones too, and anything that avoids system reboots has to be good since you have less work interruptions.
A look at Emacs
10th August 2010It's remarkable what work can bring your way in terms of technology. For me, (GNU) Emacs Has proved to be such a thing recently. It may have been around since 1975, long before my adventures in computing ever started, in fact, but I am asking myself why I never really have used it much. There are vague recollections of my being aware of its existence in the early days of my using UNIX over a decade ago. Was it a shortcut card with loads of seemingly esoteric keyboard shortcuts and commands that put me off it back then? The truth may have been that I got bedazzled with the world of Microsoft Windows instead, and so began a distraction that lingered until very recently. As unlikely as it looks now, Word and Office would have been part of the allure of what some consider as the dark side these days. O how OpenOffice.org and their ilk have changed that state of affairs...
The unfortunate part of the Emacs story might be that its innovations were never taken up as conventions by mainstream computing. If its counterparts elsewhere used the same keyboard shortcuts, it would feel like learning such an unfamiliar tool. Still, it's not as if there isn't logic behind it because it will work both in a terminal session (where I may have met it for the first time) and a desktop application GUI. The latter is the easier to learn, and the menus list equivalent keyboard shortcuts for many of their entries, too. For a fuller experience though, I can recommend the online manual, and you can buy it in paper form too if you prefer.
One thing that I discovered recently is that external factors can sour the impressions of a piece of software. For instance, I was using a UNIX session where the keyboard mapping wasn't optimal. There's nothing like an unfamiliar behaviour for throwing you off track because you feel that your usual habits are being obstructed. For instance, finding that a Backspace key is behaving like a Delete one is such an obstruction. It wasn't the fault of Emacs, and I have found that using Ctrl+K (C-k in the documentation) to delete whole lines is invaluable.
Apart from keyboard mapping niggles, Emacs has to be respected as a powerful piece of software in its own right. It may not have the syntax highlighting capabilities of some, like gedit or NEdit for instance, but I have a hunch that a spot of Lisp programming would address that need. What you get instead is support for version control systems like RCS or CVS, along with integration with GDB for debugging programs written in a number of languages. Then, there are features like file management, email handling, newsgroup browsing, a calendar and a calculator that make you wonder if they tried to turn a text editor into something like an operating system. With Google trying to use Chrome as the basis of one, it almost feels as is Emacs was ahead of its time, though that may have been more due to its needing to work within a UNIX shell in those far-off pre-GUI days. It really is saying something that it has stood the test of time when so much has fallen by the wayside. Like Vi, it looks as if the esteemable piece of software is showing no signs of going away just yet. Maybe it was well-designed in the beginning, and the thing certainly seems more than a text editor with its extras. Well, it has to offer a good reason for making its way into Linux too...