I TeX therefore iPad

Introduction

I have a new toy. It’s an iPad. Naturally the first thing that I tried to do was install TeXLive 2011 on it. When that didn’t work, I tried to take it back. When Apple disagreed with my reason (“Not able to run the best typesetting software”), I figured I’d just have to make the best of a bad job.

Actually, that’s a complete load of rubbish. The reason why it is rubbish is quite important to what I plan on writing here, so I’ll explain more below the fold. Above the fold, let me just explain what this article is. It is an account of my early days with the iPad with particular emphasis on anything vaguely relevant to my TeX addiction. If that interests you, read on.

Views and Reviews

This is not a review. Something that I learnt early on was that reviews are useless for making decisions about iPad stuff. They are always out of date and never concentrate on the important stuff. Videos are a bit better – whilst they have the same date issues, in a video you see the whole thing working, including those bits that the reviewer doesn’t think are important. Even so, for actually deciding which application to use, the best thing to do is email the developer. If they don’t answer (in a reasonable time, don’t expect a quick answer the day before the next update of the operating system is released), don’t use the application. If they do answer, they’re the ones who know best the capabilities of the application, and if they are sufficiently intrigued by your scenario, you might just get lucky and get a free copy¹.

So this isn’t a review. It’s an account.

The other thing to know before I begin is the circumstances under which I obtained this device. It was a birthday present (so no question of taking it back!). And I wasn’t expecting it. I was actually expecting a Kindle. So anything that this can do beyond reading ebooks is a bonus. And if there’s anything that it can’t do, well, I wasn’t looking for a new device so I can always just boot up the laptop.

So what do I use it for, and what would I like to use it for? Particularly with a view to my TeX addiction.

Presentation

One of the first things that I discovered was that a colleague was using his iPad for his lectures, which were prepared using beamer. This was quite exciting for me. I switched to using beamer-prepared lectures a couple of years ago, but this semester, because of the lecture room that I’m in, I have to lug a large laptop around with me. The prospect of using the iPad was therefore quite interesting. However, as I’ve been using PDFs for presentations for a couple of years now, I’ve worked out a system that I’m happy with and it has certain aspects that I’d be reluctant to give up. My non-IPad system uses xournal, a program for drawing on top of PDFs. Actually, my version is ever-so slightly hacked (the source code is beautiful: I’m no programmer but figuring out a couple of little hacks was very easy). The key features of the set-up are as follows.

• Clean, full screen display. This was actually one of my hacks. The external screen mirrors the display, so it’s important that only the absolutely necessary icons be shown.

• Fast, clean page transitions. Because PDF presentations simulate slide transitions by whole new pages, it is important that page transitions work by simply replacing one page by the next with no fuss so that there is the illusion of new material just appearing alongside the old material. One corollary of this is that the PDF should be processed when loaded, not as each page is rendered.

• Easy annotation, including highlighting. The ability to do this was what decided me that it was “safe” to use a projector instead of a chalkboard. It is a rare talk where I do not change my mind about what I want to say in the middle.

• Easy postprocessing of the annotated document. This is actually another of my hacks. A minor addition to xournal makes it possible to save only the annotated pages. Since I now use a wiki for the course pages, I can upload the annotated pages straight from the computer for the students to be able to see straightaway (before, I’d save it as a new PDF and then extract the pages, but as that had to happen later, it often happened much later).

There are plenty of presentation applications for the iPad, and there are plenty of PDF annotation applications. But the right combonation of the two was difficult to track down. In the end, there are four applications that are worth mentioning. Three that are usable, and one “honourable mentions”.

1. The one that I’ve ended up using most is iAnnotate². The only real difficulty with this application is that it doesn’t recognise one of the projectors that I regularly use as a projector, just as an external display, and that messes up the projected display. Fortunately, the fullscreen mode works okay and is almost as good as the presentation mode. Its annotation support is excellent (surprise, surprise, given the name) and I can email myself a copy of just the annotated pages which is almost as good as being able to upload them there and then.

   Conclusion: definitely usable, nothing annoying, just needs a little polish on the display mode.

2. Another that is definitely usable is 2screens. As the name suggests, the focus of this application is on the presentation side. Their aim (as I understand it) is to be a universal presentation application. They certainly have made the presentation aspect very nice, with good use of the dual screens. Their desire to be a universal presentation application does mean that their annotation system is somewhat … unusual – though it makes sense. Since not all presentation stuff comprises slides that can be written upon, the annotation system can be thought of as working by putting a sheet of glass in front of the screen and writing on that. The practical upshot of that is that the annotation is separate from the presentation. In particular, it is possible to change the background without changing the annotations. And once the annotations are cleared, you can’t get them back. A partial fix is to save a copy of an annotated slide before moving to the next. I’m told
   that there are plans to do this automatically, and plans to make these snapshots available to the presentation. Those will be valuable features.

   Conclusion: definately usable, best for when you don’t anticipate all that many annotations. (And practise with the annotation stuff beforehand!)

3. GoodNotes is a great example of why reviews don’t work. When I first got the iPad I found an application called “eNote Taker” which worked as a presentation application. It then got updated, and renamed to “GoodNotes”. Unfortunately, the update introduced sliding page transitions. So I was going to give this an “honourable mention”. But while I’ve been writing this it’s been updated again and instantaeous page transitions are back (to stay, I hope – I did email the developer to say how useful they would be). So now it’s “definitely usable”.

   Although primarily a PDF annotator, its interface is neat enough that it works well as a presentation application as well. Its simplicity works in its favour as well. Indeed, when using a projector that iAnnotate doesn’t recognise as a projector then I’ll use GoodNotes rather than iAnnotate because there’s less risk of tapping on the wrong part of the screen and bringing up an unwanted menu. It is also the first one that I used for presentations because it was the first PDF annotator that I found without annoying page transitions.

4. Explain Everything is an application that gets an honourable mention. It’s another presentation application, but it takes annotation seriously. It doesn’t make special use of a separate screen, but in presentation mode then its toolbar is very discreet. Its main focus is actually recording presentations, but you don’t have to use this bit (a Norwegian lecture is 2 hours long which is a bit much for an iPad to record). The only reason that this gets an “honourable mention” instead of “usable” is a strange bug which means that when you load in a PDF from LaTeX then it doesn’t get rendered quite right. There’s a small offset which accumulates, and by the length of one of my beamer lectures the offset is too much.

   Conclusion: if it weren’t for the offset, it would be definitely usable.

In conclusion, it is possible to use an iPad for presentations. A few minor things that can catch you out are: make sure it has a decent charge since the power cable and the VGA output use the same socket; invest in a stylus (or build your own) as it’s much easier to do serious writing with one; I don’t know of a way to have a remote for switching pages so you have to keep returning to the iPad to change slides.

Reading Articles

I have considerably less to say about reading PDFs than presenting them (remember this is not a review, just an account). This is probably because reading a PDF is a fairly normal thing to do with one so there are good applications designed just for that purpose. For reading articles (not ebooks), I mainly use one called GoodReader. Its annotation capabilities are a bit basic (writing, in particular, isn’t great) but are just fine for circling or underlining stuff. It is very easy to load documents into it, downloading from the web or via Dropbox (the unofficial iPad file system!). The fantastic feature of GoodReader is that it is possible to specify a crop for the document (with different settings for even and odd pages if desired). A standard LaTeX document is just about the right size on an iPad screen (in portrait aspect) so long as it is cropped properly.

Having GoodNotes open as the “next application” means that with iOS5 it is really easy to go between the reader and a note-taking application using the four-finger swipe³.

Reading articles on the iPad finally gives me a way to read articles in comfort without having to print large quantities of pages. I can now learn about Khovanov homology while sitting by the swimming pool waiting for my kids to finish their swimming lesson.

Writing Articles

This is perhaps the biggest surprise. It is actually possible to write a LaTeX document on an iPad. There are plenty of text editors, but technical possibility is not enough. It’s also a question of how easy it is, and whether it would get too annoying.

From one of my previous posts, you might guess that one thing that would be quite important would be the keyboard. The standard iPad keyboard is quite limited, just the letters and a couple of other keys. Getting numbers and punctuation involves swapping keyboards which is highly irritating. So the most important feature is to be able to extend and configure the keyboard. Once again it is very difficult to figure out if an application has this facility. Many text editors have extra keys, but it is not clear which have customisable extra keys.

I found an application called Fast Keyboard which adds an extra two rows above the regular keyboard and it is free (supported by adverts, which can be removed for a small fee). What is more, those two rows are completely configurable, and aren’t restricted to single characters. So as well as the obvious backslash and braces, I have a key for \begin{ and one for \end{. I can also partially simulate Emacs’s behaviour with double quotes by having keys for ‘‘ and ``.

Again, though, there is a difference between technically possible and actually being able to do it. “Touch typing” takes on a whole new meaning on a touch screen! My typing method is completely different. Because I tend to use the iPad when I’m not at a desk, I need one hand to hold the iPad so can only type one-handed. But that works. With the small keyboard (in portrait orientation), two hands get in the way of each other. Also, because the keyboard is just below the text, the necessity of typing without looking at your fingers us greatly reduced. So one-handed touch typing with watching what you are doing is actually quite possible. My error rate is a little high, but I’ve not had much pratice yet, and it isn’t excessively so.

I’ll not write a long article on it (I doubt), but a 2500 word blog post is just fine.

Other Things

The phrase “There’s an app for that” is rapidly entering the lexicon, and with good reason. The number and range of applications is quite astounding (and thanks to the amazing Project Gutenberg you can read Astounding on your iPad). Here’s a few more for TeXers to consider.

• Detexify (the application doesn’t have a web page that I can find). Technically an iPhone application, nonetheless it works fine on the iPad and is fantastic there. If it were an iPad-specific application, I’d say it was worth getting an iPad just for this.

• miniDraw. So far, this is the best I’ve found that allows me to draw and manipulate vector graphics with cubic beziers – just right for sketching TikZ pictures.

Conclusion

I have a phrase that I use to sum up my attitude to computers:

The computer should do what I want it to do, not the other way around.

It’s been a bit of a struggle, but I think that I have tamed my iPad so that it does now do what I want. I’d also say that the struggle has been worth it because in the course of taming it, I’ve found out a few things that I wasn’t expecting. In fact, adapting it to my work habits (and adapting my work habits to it) has been a lot smoother than with more “traditional” iPad acivities such as music and photos. But that’s another story.

An iPad has features that a TeX-addict can make use of. It certainly is not a replacement for a laptop, or a desktop, but as I said right at the start, I wasn’t looking for one. Rather, I’d say that it is the “missing link” between a computer and a pad of paper.

I can’t think of a better concluding statement than to say that this blog post (of about 2500 words) was written in LaTeX on the iPad, and was variously written while sitting with my feet up on my desk, by the side of the swimming pool, and lying on the sofa. I’m going to ask for a sofa in my office now so that I can make the most of it.