Hi Ronen,

Very interesting ideas --- thanks for sharing. It occurs to me you could
get a good start to the 2-projector solution you describe by telling your
monitor setup that the screens are above & below, then stretching your LyX
window vertically "across" the two. Then when you reach the end of the
"right" screen, its contents would be scrolled onto the "left" screen.

On the topic of class presentations using LyX, I thought I'd also share my
current experience.

Since the equations I deal with in my current teaching are too cumbersome
to type in real time (even with LyX), I have been using beamer to generate
projector slides. However, I really wanted fine-grained control of display
to support the kind of interactive development of the material in class
that one can achieve with a blackboard.

I discovered that (with a little ugliness) it is possible to use some of
beamer's more complex visibility constructs (e.g., \only and \onslide)
inside math mode, in ways that are not obvious from the beamer
documentation. I've attached an excerpt from one of my lectures to
illustrate what I mean. This kind of control lets you replicate many
aspects of dynamically writing and erasing on the blackboard; and in fact,
I have found the process of constructing these sequences a valuable tool in
thinking about how to arrange and develop the material in class. (For
drawings or additional clarifications, I still use the blackboards adjacent
to the projector screen, but there usually few enough of these that I don't
need to erase anything.)

With fine-grained animation, the lecture presentations end up being
hundreds of PDF pages, but I have had no problems with this because:

* to generate a print version with no animations, I need only add "handout"
under Document >> Settings >> Document Class >> Class options >> Custom

* the presentation PDF compresses to nearly the same size as the handout PDF

* going forward and backward during presentation can be done very quickly
(at least, in the evince document viewer) by simply holding down the Page
Up or Page Down key, or using beamer's automatically inserted hyperlinks.

As Ronen described, I find the freedom of not writing and erasing on the
blackboard greatly improves my ability to face the class and devote
attention to leading the presentation and discussion of the material. For a
small class, I actually stay seated most of the time to improve the

In terms of LyX development, certainly the ability to insert arbitrary ERT
in math mode would ease this approach, though this is clearly true for many
other things as well, and macros always provide a workaround. Further
beamer integration generally could be nice, but none of this is really
holding me up.

The only idea I've thought about implementing near-term is a setup I saw
described somewhere that allows the presenter to have two separate document
viewers (one on the laptop, one on the projector) both operating in
presentation mode simultaneously, that both advance with a key press. This
is not LyX-specific, and would allow the presenter to either (a) play a
copy of the presentation "ahead" on the laptop to see what's coming next,
or (b) use the "notes" features of beamer or other packages (or use a
lecture notes file) to guide verbal delivery.

I'd be interested to hear what other instructors have come up with.

- Thomas

On Thu, Apr 5, 2012 at 2:56 PM, Ronen Abravanel <ron...@gmail.com> wrote:

> Hello,
> I've been using LyX for writing notes and papers for the last ~8 years,
> and lately I started using lyx in a new form, that might be of an interest
> to others: As a presentation tool.
> The general idea is simple: As I teach (modern physics for EE students),
> instead of writing on a white-board with my awful handwrite, I just type
> the lesson into a computer connected into a projector. Both text and math.
> I stand in front of the class, talking to them, looking at them, and type.
> Occasionally I leave my laptop and draw something on the board, or do some
> demonstration, For illustrations, I'm either insert them into the document
> (god bless inset-insert graphics and the minibuffer), or, if the figures
> are simple, and I find that it may be instructive to draw them gradually, I
> draw on the board.  If I wont to remind the students something from earlier
> part of the class, I split the display into Left\Right half, and scroll one
> of them up while continue working on the other half.
> This methods have many advantages
> Over handwriting on the board:
> * The main one, the the one lead me to do it: Not forcing the student dose
> not have to read my bad handwrite, and I don't spend much time on writing
> neatly.
> * I'm always facing the class -- I'm not turn my back to them as I write
> (only look little bit down, at my screen), so I can see them, and they can
> see my face and hear me better.
> * When I have complex illustration, I can just add it to the document..
> And over pre-made slides:
> * Saves time -- I do not have to typeset slides in advance (Also:
> Beamer+Hebrew+LyX is a disaster, so it would force me to turn into OO\MS PP
> or something like that, which is almost as bad)
> * Dynamic -- I can write notes and skip\add steps and lines during the
> class.
> * Slow -- Doing math on slides is bad. Most of the time, the slides are
> too crowded to understand, and fill-up at once, and not character by
> character as one would like on the board. When I'm typing with the class,
> I'm keeping on slow paste, so the can understand the math and follow by it.
> But also some disadvantages:
> * My screen is about 1/4 the size of the whiteboard, and LyX is rather
> lossy in screen-space. So, instead of just pointing into other parts of the
> board, I have to split\scroll.
> * The class's screen reaches to low, So, in order to let the students see
> the all screen, I switch into fullscreen mode, and then add toolbars from
> below in order to push the effective screen upwards.
> * When writing in lyx, one always writes on the bottom part of the screen.
> There is no good way  (after writing more then screen-full of text) to
> start from top, add lines from beneath and then shift to a "new" screen
> when I fill it.
> * It's rather ugly when I write \latexCommand in red, and just when I'm
> finish its render into symbol.
> Few points one can improve (mostly theoretical. some will demand big many
> expanse from my university, and some are "Itches I should scratch when I'll
> have time to code")
> * Create half-slide-mode in lyx: Copy one document into another, character
> by character, When I'm pressing a single key. It will require preparation
> (but anyhow, I prepared the lesson in advance as a lyx document... I don't
> remember all by heart , and anyway, it's still a lot easier then creating
> lyx\beamer slides), but it will save effort and mistakes during the class ,
> while still enable grate flexibility.
> * I wish I had 2 VGA output and 2 projectors, and LyX would switch from
> the end of one screen into the top of a new-clean-page at the other screen
> whenever I fill out the 1st. That would be just perfect :-P.
> * I should get something higher then the teacher's table to put my laptop
> on. For now, I have to bend over it, and my back is not happy.
> Anyway, I'm doing it for a month now,  3 hours a week, and the  experience
> for both me and my students is positive. If you have to teach stuff and
> don't wont to write on a board, you may consider using lyx. it's fun!
> - Ronen.
> --
> ______________________________________
> Thomas Coffee
> Massachusetts Institute of Technology
> Department of Aeronautics & Astronautics
> Space Systems Laboratory
> 617.549.5492
> Please avoid sending attachments in proprietary formats like Word or
> PowerPoint.
> For more information, see
> http://www.gnu.org/philosophy/no-word-attachments.html
> ______________________________________

Attachment: lecture 05 excerpt.lyx
Description: application/lyx

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