SWeave with non-R code chunks? - shell

I often use Sweave to produce LaTeX documents where certain chunks are produced dynamically by executing R code. This works well - but is it also possible to have code chunks that are executed in different ways, e.g. by executing the code in the shell, or by running Perl, and so on? It would be helpful to be able to mix things up, so I could do things like run some shell commands to fetch some data, run some perl commands to pre-process it, and then run R commands to analyze it.
Of course I could use all R chunks and use system() as a poor-man's substitute, but that doesn't make for very pleasant reading in the document.

The new new thing (for multi-language, multi-format) docs may be dexy.it which for example these guys at opengamma.org use as the backend.
Ana, who is behind dexy, is also giving a lot of talks about it so also look at the dexy blog.

It's not directly related to Sweave, but org-babel, which is part of Emacs org-mode, allows to mix code chunks of different languages in one file, pass data from one chunk to another, execute them, and generate LaTeX or HTML export from the output.
You can find more informations about org-mode here :
http://www.orgmode.org/
And to see how org-babel works :
http://orgmode.org/worg/org-contrib/babel/

There is certainly no easy way to do this other than through either foreign language interfaces from R (maybe through inline if it's supported), or system(). For what it's worth, I would just use system(); that should be easy enough.
You can see this previous question about having a Sweave equivalent for Python, where one of the respondents actually creates a separate interface. This can give you a sense what what it would take to embed other languages which may not already be supported. At a minimum, you have to do major hacking on the Sweave driver.

Do you know emacs" org-mode and, more specifically, Babel? If you already know Emacs or are willing to switch to Emacs, then org-mode and Babel are the answer to your question(s).
For instance, I am currently working on a document which contains some shell-scripts, does computations with R and creates flow charts with dot (graphviz). Org-mode can export a variety of formats, e.g. LaTeX (that's what I use).

There is the StatWeave project which uses java rather than R to do the weaving, but will run multiple programs instead of just R. I don't know how hard it would be to get it to do Perl or other programs like that, but the homepage indicates that it already works with R, SAS, Stata, and others:
http://www.cs.uiowa.edu/~rlenth/StatWeave/

Related

julia: static analyzer/linter for the command line

im looking for a shell command-line tool to lint julia scripts (a static analyzer), eg.
local:~ $ linter(myjuliascript.jl)
which will produce its output to terminal => text with linter results = either
// messages inlined with text of myjuliascript.jl or
...
...
// messages indicating line numbers of myjuliascript.jl
...
...
i found this, https://github.com/tonyhffong/Lint.jl, but it does not look promising (does not compile).
question: do you know of any good-quality command-line tool with which to lint julia scripts?
id rather avoid plugins to IDE's, since im a little tired of IDEs; often they are too much kung-fu-fighting with too little benefit. eg. tried to get the VS code julia linter working, no luck; VS code, julia linter doesn't work (on mac)
The closest thing currently available appears to be https://github.com/julia-vscode/StaticLint.jl. While you could technically call this from the command line if so desired using, julia -e, the interface would not seem to be very conducive to that sort of usage.

Is there a way to use load-mode for files in DrRacket?

I would like to use DrRacket in the same way that it works for some of the ‘legacy languages’. In particular, I would like to go through a file as if it were a sequence of commands issued to the interpreter, and not as a module.
Essentially I want to run at least one file in load-mode, but I’m not sure if it’s possible to do it using DrRacket.
Ideally, I could:
*Specify a file that sets the language and maybe loads some modules, which runs by default at startup.
*Then load a file that is not a module (and has no #lang specification) and run it.
It’d also be nice (since I want to use Scheme) if it would allow redefinitions, just as the legacy languages do.
Yes you can, and in fact, the 'legacy languages' (and 'teaching languages') are actually just implemented as DrRacket Plugins. You can remove them from your copy of DrRacket and even add new ones.
There are various ways to do this depending on if you are okay with a #lang (or #reader) saved in the file. If you're not, its still doable, you just need to use drracket:get/extend:extend-unit-frame to add your tool to DrRacket, and possibly drracket:get/extend:extend-definitions-text to easily extend the definitions window.
I won't go into the details of making a generic DrRacket plugin here, that belongs in a different question...also the DrRacket Plugins Manual has the information you need.1 I will, however, point you in the direction of how you can use DrRacket in load mode out of the box.
Check out the racket/load language. It is designed to run each expression in the top level as if you were at a REPL typing it. I find it very useful for testing the differences between Racket module and top level interactions.
Of course, if you don't make a DrRacket plugin, you will still need to put:
#lang racket/load
at the top of your file, but you otherwise get a 'legacy mode' out of the box.
1If it doesn't please continue to ask questions, and of course we always love help from anyone who is willing to contribute. <3

Run user-submitted code in Go

I am working on an application which allows users to compare the execution of different string comparison algorithms. In addition to several algorithms (including Boyer-Moore, KMP, and other "traditional" ones) that are included, I want to allow users to put in their own algorithms (these could be their own algorithms or modifications to the existing ones) to compare them.
Is there some way in Go to take code from the user (for example, from an HTML textarea) and execute it?
More specifically, I want the following characteristics:
I provide a method signature and they fill in whatever they want in the method.
A crash or a syntax error in their code should not cause my whole program to crash. It should instead allow me to catch the error and display an error message.
(In this case, I am not worried about security against malicious code because users will only be executing my program on their own machines, so security is their own responsibility.)
If it is not possible to do this natively with Go, I am open to embedding one of the following languages to use for the comparison functions (in order of preference): JavaScript, Python, Ruby, C. Is there any way to do any of those?
A clear No.
But you can do fancy stuff: Why not recompile the program including the user provided code?
Split the stuff into two: One driver which collects user code, recompiles the actual code, executes the actual code and reports the outcome.
Including other interpreters for other languages can be done, e.g. Otto is a Javascript interpreter. (C will be hard :-)
Have you considered doing something similar to the gopherjs playground? According to this, the compilation is being done client-side.

syntax-check a VimL script

I have a sizable vim script (a .vim file, in viml syntax). I'd like to check (but not execute!) the file for simple syntax errors.
How do I accomplish this?
I just want a very rough syntax check. Something along the lines of perl -c or pyflakes.
Here is a syntax checker for VimL.
https://github.com/syngan/vim-vimlint/
I don't think (I'm relatively sure, as much as one can be) one exists. VimL is an internal language of Vim (and only Vim), and there aren't many tools developed for it.
I tried searching on vim.org and several other places, with no luck. Not suprising, because I've never heard of one either.
So you're either stuck with running the script, or switching to an outside language like Python, Perl or Ruby.
https://github.com/osyo-manga/vim-watchdogs
vim-watchdogs, apparently, is a syntax checker for vim, it says that it supports many languages, including vimL
if you use vundle, you can just drop this into your vimrc:
Plugin 'git://github.com/osyo-manga/vim-watchdogs.git'
..and then run:
:PluginInstall
..to set it up (vundle is a very nifty plugin manager) If you have syntastic, you might want to be careful and disable it first, and then see if it is an adequate replacement (since it says it supports all those languages anyway).
It is a safe bet that when you have multiple syntax checkers going, you will need to put your "dogs on a leash", so to speak; by configuring one to check languages that the other one does not, and vice-versa. If you do not, there will be at best collisions, duplications, or misdirections. At worst, you will have all of the above and more.
Make sure that you always backup your ~/.vim directory (or your VIMRUNTIME directory if you install things on a global level), you will be glad you did. Hope that helped you or someone else out, good luck! Sorry you had to wait 7.5 months for a response, heh :)
There's now a second option: vim-lint (as opposed to vimlint)

How can one get a list of Mathematica's built-in global rewrite rules?

I understand that over a thousand built-in rewrite rules in Mathematica populate the global rules table by default. Is there any way to get Mathematica to give a full or even partial list of those rules?
The best way is to get a job at Wolfram Research.
Failing that, I think that for things not completely compiled into the kernel you can recover most of the rules/definitions. Look at
Attributes[fn]
where fn is the command that you're interested in. If it returns
{Protected, ReadProtected}
then there's something you can get a look at (although often it's just a MakeBoxes (formatting) definition or a AutoLoad/Stub type definition). To see what's there run
Unprotect[fn];
ClearAttributes[fn, ReadProtected];
??fn
Quite often you'll have to run an example of the command to load it if it was a stub. You'll also have to dig down from the user-facing commands to the back-end implementations.
Eventually you'll most likely reach a core command that is compiled into the kernel that you can not see the details of.
I previously mentioned this in tips for creating Graph diagrams and it got a mention in What is in your Mathematica tool bag?.
An good example, with a nice bite-sized and digestible bit of code is Experimental`AngularSlider[] mentioned in Circular/Angular slider. I'll leave it up to you to look at the code produced.
Another example is something like BoxWhiskerChart, where you need to call it once in order to load all of the code. Then you see that BoxWhiskerChart proceeds to call Charting`iBoxWhiskerChart which you'll have to unprotect to look at, etc...

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