Kindle as a Tool for Mathematicians?

Following suggestions in an MO discussion of "tablets" good for math, I spent a few dollars and acquired "GoodReader" and "iAnnotate PDF" and "Note Taker HD". I already had "Pages" on my iPad ("1", not "2"), as well as iBooks.

With the "zoom" capability, they're all at-least-ok for reading PDFs. The iBooks is obviously not really aimed at this application. The "GoodReader" has functionality similar to the parts of Adobe Acrobat Pro that I use on my desktop Mac to mark up drafts (and other), in touch-screen form. Easy to organize files, too, at least in the sense that the interface for doing so is consonant with other interfaces familiar to me. The "Pages" creation of PDFs is not so much what I use, tho' it is the only way I can really produce PDFs on the iPad. I've not had occasion to compare iAnnotate yet.

The "note-taker HD" is quite striking, tho' I've not yet tried using it seriously. I do intend to attempt some note-taking (writing with my finger!): the resulting PDF file can be emailed, scp'd, etc., rather than needing photocopying... even if one eventually retypes-and-discards it.

In summary, despite the relative tininess, zoom makes it hugely better than lugging stacks of paper, to begin with. A very small laptop might compete, if it had "zoom", to make it worthwhile carrying the extra pound of weight... In fact, tablets fit under airplane seats much-much-much better than even small laptops. Battery life is much better, too.

I intend to try taking notes with the "note taker HD" sometime soon, to gauge the feasibility of writing as fast with my finger (stylus?) as with a pen. Obviously some of the issue is the feedback loop.

I believe that if one acquires the correct cable, that wide-plug from an iPad can run a TV/projector (tho' of course the battery life will be worse).

The combination experiment, which I may perform this coming academic year, is using the mark-on-it-with-your-finger possibility, together with the projection possibility, to give lectures via iPad. My previous objection to "projector" talks has mainly been the static-ness (at least as the state most speakers default into) and non-adaptibility. Being able to scribble and high-light a projected typset screen, as well as "writing in the margin" (with my finger...or stylus) may allow a sufficiently dynamic version...

... not to mention allowing preservation of the marked-up version as a PDF, made available on-line for students, etc.

That is, an iPad with a teensy further investment in "apps", at least if one has a Mac machine to sync it with, seems quite excellent given the trade-offs.

Edit (14 Oct 2012): Used "Note Taker HD" all last year, 2011-2012, and it worked pretty well, although since I was just marking on PDFs I didn't get around to using the "zoom" feature to make small, precise marks. Since then, I've experimented further with various further possibilities: Penultimate (no small writing, but trivially easy to use), Notes Plus (pretty-good small writing), Notability (acquired recently), and just now, at the urging of hhh, "UPad". As suggested by hhh, the "small writing" (a.k.a. "zoom") in UPad is somewhat better quality than the others, insofar as it remains equally responsive to stylus pressure, etc., rather than losing that granularity of control.

I note that a somewhat different style of writing/note-taking seems necessary/better with these devices rather than paper-and-pen/pencil, namely, that color-emphasis, highlighting, cut-and-relocate, and "undo" change the ground-rules significantly. I do not claim to have figured it out...

The possibility of making a recording (of someone's talk) syncrhonized with note-taking exists in many of these apps, but there is the complication that most speakers do not anticipate that anyone is recording them, etc., either in terms of intellectual property or "attributable quotes", so I've not touched that.

I will share my experience here.

At first I also bought a Pocketbook e-reader, specifically the 902, which has a larger screen. It handled both DJVU and PDF files, which was important to me. The DJVU rendering was slow, however, and it had serious lag issues with large files. But all the math was perfectly rendered, zoom worked, etc.

I eventually got rid of my Pocketbook because I found the device somewhat unreliable. It was also clear that reading DJVU files on an e-reader is not the joy you might think it is. Specifically, these are normal (A4) sized pages, being shrunk to fit the screen. I downloaded a few programs to help with the margins, but still, it was difficult/not worth it to read DJVU files this way.

I then purchased a Kindle DX, which can handle PDF files, but not DJVUs. The Kindle is an incredible product, and works very well. Still, it will lag on larger PDF files, and several times I have had to trim margins on my laptop before putting them on the Kindle. This is really nothing to do with math however: I don't think there are any e-readers out there which handle PDF files like this well.

Now there a couple of options. One is to convert the PDF files to an AZW (or even MOBI) file. In my experience, this fails miserably. Even without any formulas/math type, the spacing and sentence structure is essentially ruined. With math? disastrous results. And if there are pictures, forget it.

The other option, which isn't always available, is to get your hands on the TeX source. I use this option for any arXiv papers I download, for example. There you can resize the font, margins, etc., to optimize for Kindle viewing. There are measurements out there which give exact dimensions for the viewing window of a Kindle. This option (which again, isn't always a possibility) is certainly the best. Reading a paper on the Kindle this way is just as enjoyable as reading a hard copy.

In the end, the books I do have as PDF files I trim myself (using pdfTK and a Java program called Briss), and then put them on the Kindle as PDF files. I view it rotated 90degrees, because this increases the magnification.

The articles I can get as TeX files, I adjust the margins/font size etc. (this is based on the paper itself; for example, large figures require different processing than a short, all-text paper). Then I convert to PDF and put on my Kindle. Again, these are the nicest PDFs on my Kindle.

Finally, I would like to mention that several prominent math books (a few by John Stillwell for example) are now available in Kindle format on Amazon. I haven't purchased any of these, but presumably the publisher simply changed the margins/text size in the TeX file, as I do for the articles.

I have the previous-generation Kindle, though I think the software and screen are essentially the same. I think PDF would probably be the only convenient format and letter-size PDFs are a bit small to read without having to zoom and pan. Personally, I wouldn't want to deal with a textbook on it—in fact, I wouldn't want to deal with textbooks on any tablet device I've seen thus far because you lose physical features like looking at two books at once and flipping through the book—but I'd certainly consider using it for articles or other shorter works.