How to cross-reference an equation in an R help file/roxygen2 - r

I'm in the process of documenting some of my functions for an R package I'm making.
I'm using roxygen markup, though that is largely irrelevant to my question.
I have put equations into my documentation using \deqn{...}. My question is:
Is there a way to cross-reference this equation later on?
For example, in my Rd file:
\deqn{\label{test}
y = mx + b
}
Can I later do something like:
Referring to equation \ref{test}, ...
I've tried \eqref{test}, \ref{test} (which both get "unknown macro" and don't get linked ), and also \link{test} (which complains it can't find function test because it's really just for linking to other functions).
Otherwise I fear I may have to do something hacky and add in the -- (1) and Refer to equation (1) manually within the \deqn etc in the Rd file...
Update
General answer appears to be "no". (awww...)
However, I can write a vignette and use "normal" latex/packages there. In any case, I've just noticed that the matrix equations I spent ages putting into my roxygen/Rd file look awful in the ?myFunction version of the help (they show up as just-about literal latex source). Which is a shame, because they look beautiful in the pdf version of the help.
#Iterator has pointed out the existence of conditional text, so I'll do ASCII maths in the .Rd files, but Latex maths in the pdf manual/vignette.

I'm compiling my comments above into an answer, for the benefit of others.
First, I do not actually know whether or not .Rd supports tagging of equations. However, the .Rd format is such a strict subset of LaTeX, and produces very primitive text output, that shoehorning extensive equations into its format could be a painful undertaking without much benefit to the user.
The alternative is to use package vignettes, or even externally hosted documentation (as is done by Hadley Wickham, for some of his packages). This will allow you to use PDFs or other documentation, to your heart's content. In this way, you can include screenshots, plots, all of the funkiest LaTeX extensions that only you have, and, most significantly, the AMS extensions that we all know and love.
Nonetheless, one can specify different rendering of a given section of documentation (in .Rd) based on the interface, such as text for the console, nice characters for HTML, etc., and conditional text supports that kind of format variation.
It's a good question. I don't know the answer regarding feasibility, but I had similar questions about documenting functions and equations together, and this investigation into what's feasible with .Rd files has convinced me to use PDF vignettes rather than .Rd files.

Related

Using R's exams package for assignments: Is it possible to add question hints?

The exams package is a really fantastic tool for generating exams from R.
I am interested in the possibilities of using it for (programming) assignments. The main difference from an exam is that besides solutions I'd also like hints to be included in the PDF / HTML output file.
Typically I put the hints for (sub)-questions in a separate section at the end of the PDF assignment (using a separate Latex section), but this requires manual labour. These are for students to consult if they need help getting started on any particular exercise, and it avoids having them look at the solutions directly for hints on how to start.
An assignment might look like:
Question 1
Question 2 ...
Question 10
Hints to all questions
I'd be open to changing the exact format as long it is possible to look up hints without looking up the answer, and it remains optional to read the hints.
So in fact I am looking for an intermediate "hints" section between the between the "question" and "solution" section, which is present for some questions but not for all.
My questions: Is this already possible? If not, how could this be implemented using the exams package?
R/exams does not have dedicated/native support for this kind of assignment so it isn't available out of the box. So if you want to get this kind of processing you have to ensure it yourself using LaTeX for PDF or CSS for HTML.
In LaTeX I think it should be possible to do what you want using the newfloat and endfloat packages in the LaTeX template that you pass to exams2pdf(). Any LaTeX template needs to provide {question} and {solution} environments, e.g., the plain.tex template shipped with the package has
\newenvironment{question}{\item \textbf{Problem}\newline}{}
\newenvironment{solution}{\textbf{Solution}\newline}{}
with the exercises embedded as
\begin{enumerate}
%% \exinput{exercises}
\end{enumerate}
Now instead of the \newenvironment{solution}... you could use
\usepackage{newfloat,endfloat}
\DeclareFloatingEnvironment{hint}
\DeclareDelayedFloat{hint}{Hint}
\DeclareFloatingEnvironment{solution}
\DeclareDelayedFloat{solution}{Solution}
This defines two new floating environments {hint} and {solution} which are then declared delayed floats. And then you would need to customize these environments regarding the text displayed within the questions at the beginning and the listing at the end. I'm not sure if this can get you exactly what you want, though, but hopefully it is a useful place to start from.

How to make publishable tables and plots using R? [duplicate]

There are a range of tools available for creating publication quality tables using R, Sweave, and LaTeX.
In particular, there are helper functions like latex in the Hmisc package, and xtable in the xtable package. I've also often written my own code so that I could have complete control over table formatting (e.g., see this example).
However, when preparing publication quality tables a range of issues often arise:
how and when to apply numeric formatting
how to precisely control alignment of columns and cells
how to precisely control cell borders
how to convert variable labels to variable names
and so on
Beyond the high level issues of specifying the desired table format, there are issues of implementation.
When should a helper function such as xtable be used?
Which helper function should be used in a given situation?
How can the default output of helper functions be customised to particular requirements?
Question
It seems to me that the above issues are deserving of a detailed textbook-style introduction.
Are there any online or offline resources that provide a detailed overview of how to produce publication quality tables using R, Sweave, and LaTeX, and that address the issues discussed above?
Just to tie this up with a nice little bow at the time of current writing, the best existant tutorials on publication-quality tables and usage scenarios appear to be an amalgamation of these documents:
A Sweave example (source)
The Joy of Sweave: A Beginner's Guide to Reproducible Research with Sweave (source)
Latex and R via Sweave: An example document how to use Sweave (source)
Sweave = R · LaTeX2 (source)
The xtable gallery (source)
The Sweave Homepage
LaTeX documentation
Going beyond the scope of what currently exists, you may want to ask the author of The Joy of Sweave for a document on publication-quality tables specifically. It seems like he's gone above and beyond this problem in his research. In addition to the questions you've raised, this space specifically could use a style guide that, flatly, does not currently exist.
And, as mentioned in the question errata, this is a perfect example of a question for https://tex.stackexchange.com/. I encourage you to continue to ask specific questions there when you run into any difficulties in your current projects.
The package stargazer can create publication-quality - incl. using templates designed to resemble existing academic journals - from commonly used R statistical functions and packages (lm, glm, plm, svyglm, survival, pscl, AER, and others). Also good for creating summary statistics tables, and can directly output data frame content as well.
There is a tabular function in the tables package which addresses formatting, alignment and label operations. The package has a vignette which is a good starting point.
xtable has worked fine for me so far.
In combination with siunitx, and when necessary, longtable, it can produce pretty effective tables, in my opinion. With packages like booktabs and caption, the aesthetics can be pleasing too.
I am not sure this level of detail was asked for by the OP, but for what it's worth, the basic implementation could be something along these lines: https://tex.stackexchange.com/questions/41067/caption-for-longtable-in-sweave/41183#41183 (my own answer to another question).
I highly recommend ConTeXt which makes use of the TABLE package. There is a Table overview in contextgarden and an exhaustive manual.

General guide for creating publication quality tables using R, Sweave, and LaTeX

There are a range of tools available for creating publication quality tables using R, Sweave, and LaTeX.
In particular, there are helper functions like latex in the Hmisc package, and xtable in the xtable package. I've also often written my own code so that I could have complete control over table formatting (e.g., see this example).
However, when preparing publication quality tables a range of issues often arise:
how and when to apply numeric formatting
how to precisely control alignment of columns and cells
how to precisely control cell borders
how to convert variable labels to variable names
and so on
Beyond the high level issues of specifying the desired table format, there are issues of implementation.
When should a helper function such as xtable be used?
Which helper function should be used in a given situation?
How can the default output of helper functions be customised to particular requirements?
Question
It seems to me that the above issues are deserving of a detailed textbook-style introduction.
Are there any online or offline resources that provide a detailed overview of how to produce publication quality tables using R, Sweave, and LaTeX, and that address the issues discussed above?
Just to tie this up with a nice little bow at the time of current writing, the best existant tutorials on publication-quality tables and usage scenarios appear to be an amalgamation of these documents:
A Sweave example (source)
The Joy of Sweave: A Beginner's Guide to Reproducible Research with Sweave (source)
Latex and R via Sweave: An example document how to use Sweave (source)
Sweave = R · LaTeX2 (source)
The xtable gallery (source)
The Sweave Homepage
LaTeX documentation
Going beyond the scope of what currently exists, you may want to ask the author of The Joy of Sweave for a document on publication-quality tables specifically. It seems like he's gone above and beyond this problem in his research. In addition to the questions you've raised, this space specifically could use a style guide that, flatly, does not currently exist.
And, as mentioned in the question errata, this is a perfect example of a question for https://tex.stackexchange.com/. I encourage you to continue to ask specific questions there when you run into any difficulties in your current projects.
The package stargazer can create publication-quality - incl. using templates designed to resemble existing academic journals - from commonly used R statistical functions and packages (lm, glm, plm, svyglm, survival, pscl, AER, and others). Also good for creating summary statistics tables, and can directly output data frame content as well.
There is a tabular function in the tables package which addresses formatting, alignment and label operations. The package has a vignette which is a good starting point.
xtable has worked fine for me so far.
In combination with siunitx, and when necessary, longtable, it can produce pretty effective tables, in my opinion. With packages like booktabs and caption, the aesthetics can be pleasing too.
I am not sure this level of detail was asked for by the OP, but for what it's worth, the basic implementation could be something along these lines: https://tex.stackexchange.com/questions/41067/caption-for-longtable-in-sweave/41183#41183 (my own answer to another question).
I highly recommend ConTeXt which makes use of the TABLE package. There is a Table overview in contextgarden and an exhaustive manual.

R code in Sweave

I have a scientific paper under review, and a referee asked for my R code to be provided as a Sweave document. I've never heard of Sweave before, do you know what's the better way to do it?
Thanks a lot :-)
This seems a very unusual request in my opinion. I can understand a referee expecting you to provide reproducible code, but requiring a specific format is over-the-top. I would respond by providing your code. Sweave is not standard practice for academic journals.
A quick google can lead you to a lot of good resources:
http://www.stat.uni-muenchen.de/~leisch/Sweave/
http://www.stat.umn.edu/~charlie/Sweave/
http://jeromyanglim.blogspot.com/2010/02/getting-started-with-sweave-r-latex.html
http://en.wikipedia.org/wiki/Sweave
See my answer to this question: Getting R plots into LaTeX?
I personally recommend using either LyX or Eclipse (with StatET and TeXlipse) for this, although there are many options for editing LaTeX out there.
Edit:
If your script takes a long time to run, then you can also look at the cacheSweave package.

What word processor do you use for technical papers?

I've been looking for some time for a word processor to use for writing technical papers and I haven't really found one. What would really be nice to have is an editor that can handle mathematical expressions, code, and pseudo-code fairly well. I have yet to find one that works very well.
Does anyone have any recommendations?
I personally believe in LaTeX.
Benefits:
You can focus on content over form.
Use logical rather than semantic formatting (e.g., \methodname vs. just italic).
Easier to assemble large documents from multiple files.
Use text-based version control (CVS/SVN/etc.)
Widely used
Much more stable even on super-weak machines
Programmable. For example, I use macros to hide stuff, highlight stuff, obfuscate names by using a macro name with the real name but an obfuscated replacements.
See all the tips and tricks available on SO.
Output looks the same no matter which platform you compile on. Never had that luck with word, each version and each machine produces something slightly different.
My answer's long, so I want to say up front: I think you want OpenOffice Writer (I use v2.4, haven't tried 3.0 yet).
I've used Word with equation editor and LaTeX heavily in the past and OpenOffice Writer
more recently. I used the former two while writing my thesis.
LaTeX may still have advantages in quality of the output and in the ability to use text-based version control, but they're sharply diminished by OO Writer at this point.
Microsoft with equation editor, even the most recent versions, seems very weak still.
What I like about OpenOffice is that you can use the equation formatting mechanisms
in a mode where the window is split between the document you're writing and another
area where you can type very LaTeX-like formatting instructions. One of the big
strengths of LaTeX is that you get to type up something like $x \in S$ for "x is an element of S". OO Writer lets you do this and see the result.
Back when I wrote my thesis, LaTeX was preferable to Word with Eqn. Editor because of the length of my document (over 200 pages), the quality of the results, and the ease of specifying equations. LaTeX does have a disadvantage in simplicity of use that is made more acute by OO Writer.
That said, I'm sure I'd use OO Writer for conference to journal length articles (~8-15 pages v. ~15-40 pages) and also for shorter work. For thesis-length work, I'm not sure which I'd end up using: Word never worked so well for me on longer matter; I suspect OO Writer is better behaved but I don't have enough experience of it to make a firm judgement.
I like LyX (http://www.lyx.org/) -- it's a good tradeoff between "spending all your time writing your document" and "spending all your time writing markup". The most recent versions are even useable!
Apart from that, Word 2008 is actually pretty darn good, provided you use the styles and other "advanced" features.
I fully agree that LATEX is a good choice. I've used for paper in univ, including my master thesis. For LATEX I've been using Kile.
But nowadays there is interesting alternative which is DocBook with MathML extension.
LaTeX with TexMaker got me through grad school.
Depends on what you mean by "Word Processor". If you don't mind not having a WYSIWYG interface, I'd recommend LaTeX (http://www.latex-project.org/).
I wrote my final year Master's dissertation using it, which contained a lot of pseudocode, formulas, etc. Also outputs in a format fairly typical of technical papers.
I use FrameMaker.
MS Word with Mathtype. It has a number of advantages over the default Equation editor, including, but not limited to:
keyboard shortcuts
writing equations in tex mode then converting them
converting equations from "normal" to "linear" mode (the one you can use in your programs, you know a=b/c and such)
templates
no more latex. I can concentrate on the material, not the writing
Word with MS Equation for the mathematical sections.
I like DocBook and use FOP to create PDFs from it.
I use reStructuredText because it can be used in Trac, converted to PDF and HTML, have little markup overhead, and looks nice in its plain form too.
Microsoft Word is considered as the market standard word editor.
My suggestion is for you to use Authorea.
As a former postdoc (Astrophysics) and Ph.D. (Informatics) with 12+ years research experience (Harvard, CERN, UCLA), I have written technical papers for a long time. I have loved and hated LaTeX. For the past 2 years, I have worked with friends and colleagues at developing the next generation platform for writing technical/research documents collaboratively. It is called Authorea. From a technical standpoint Authorea is built on Git and takes LaTeX, Markdown, HTML (even JS, to include fancy d3.js in your papers). Bonus: you don't need to know LaTeX (or any other format) but you can easily add equations, tables, citations, and data to your papers. I hope you'll find it useful.

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