Coding with Fountain Pens

Perhaps one of the more stress inducing aspects of throwing together Ignite Ann Arbor, was figuring out how to play all our speaker’s slide decks, with 15 second auto-advance, but also with non-timed slides interspersed between, all while avoiding cross-os font imbroglios and ugly on-screen GUI manipulation. I’ll describe what I used here in nauseating detail. Hopefully this will be useful to other Ignite organizers, or anyone trying to give a talk without whipping out powerpoint.

I’ll be giving a little demo at the MichiPUG meeting July 2nd.

I settled on Impressive, a presentation framework written in python. It allows you to give a slideshow type performance using either PDF files or a directory of images as source. We asked all presenters to submit their slide decks of exactly 20 slides, in PDF format to ensure they were platform independent. We also supplied the projector resolution ahead of time so they would have that information; It was particularly relevant to Laura Fisher’s talk on ratios. I made additional slides with the Ignite template, an introduction with name and title for each speaker, and a thanks slide. I then exported these as individual one page PDFs with the presenters surname.

At this point, I had three directories (intros, presos, thanks) each with 14 PDFs, using surnames as the filename in each directory. Each presentation was to be kicked off individually. I ended up running Impressive in cygwin, although you could also run it natively. Thus I had a shell script to launch each presentation, also titled by surname. An example shell script:

impressive -T 0 -I single.info -C m.png ./intros/Ackasu.pdf ./presos/Ackasu.pdf ./thanks/Ackasu.pdf

This calls impressive on the three PDFs, which are strung together as though they were one presentation. It also sets the transition time to 0 to eliminate slide transitions, calls the info file single.info, and uses m.png (which was a 1 pixel transparent image) as the pointer icon. The info file system is one of the really powerful tools Impressive offers. You can basically add flat out python to customize the slideshow. My single.info file consisted of this:

for page in xrange(2, 22):
   SetPageProp(page, 'timeout', 15000)

Thus, a 15 second timeout was placed on each slide except the first and last. There is a -a command line option to just flat-out give every slide a particular transition time, but using the .info file let me apply the timeout to just the slides in the actual presentations.

I then made a windows shortcut calling cygwin’s bash.exe and the relevant shell script for each presenter, which I numbered with the speaking order, so that all the shorcuts were in order. During ignite, I could then just go down the list of shortcuts and running each presentation one at a time. Incidentally, we could have changed speaking order by simply reordering the shortcuts.

I think it worked really well. Impressive provided a nice slick way to organize everything and it’s visually pleasing. We didn’t use a fraction of it’s capabilities, which you might want in a differently structured presentation. For instance, you can hit to get a view of all your slides if you have to jump around, you can use a spotlight effect, there’s different transitions (ok, even though the transitions are nicely animated, please, please do not use transitions in the name of all that is holy). Check out the documentation to see what else you can do with it.

This is crazy. On the last shuttle mission, a work light knob was loose and floating between the instruments and a window. On landing the shuttle contracts and it’s wedged in there now damaging the window. They can’t get it out, and they think it will take 6 months to dissassemble that section of the orbiter. Since they’re supposed to stop flying in a year, it’s not clear if they’ll bother.

via Slashdot

I’ve been pretty busy organizing Ignite Ann Arbor 1, which is shaping up to be a fantastic event. Ignite talks are 5 minutes long, with 20 slides advancing automatically every 15 seconds. We’ve got a dozen speakers on a wide range of topics, and looking to have a great evening.

Go ahead and RSVP if you haven’t already!

I’m at http://twitter.com/ryanburns if you’re into that kind of thing.

If you’ve ever tried controlling an iPod touch or iPhone in a car dock, you probably are aware of the benefits of tactile feedback provided by mechanical controls - something that’s lacking with touchscreens. Hence this research into dynamic physical controls which double as a multi-touch display looks really interesting.

While this programmable tactile control technology looks really cool, it seems it would be too bulky for small personal devices. I never understood why the touch iPods didn’t include gestures to control playback in car situations, that would be supremely useful.

via infosthetics.com, which is a great blog btw.

A new article from space.com sheds some revealing light on the recent collision of an Iridium satellite with a defunct Soviet military satellite.

I think there was a common impression that Norad would pick up the phone and call operators if they saw an impending collision so that they could maneuver to avoid it. It seems though, that the actual state of affairs is much different.

The US Air Force publishes orbital elements, which are apparently not that accurate. In the linked article it states that the French space agency uses additional ground based radars to refine estimates if a probability looks too high. In the case of the Iridium satellite, the collision probability was 1 in 10,000 which gives an idea of the accuracy.

The Air Force does detailed analysis for human spaceflight, but for random commercial satellites, it’s up to the operator to use the orbital elements to determine a course of action.

Instead of the idea that operators are always maneuvering to avoid collisions, my new picture of the state of affairs is that a lot of satellites are pretty much flying blind and could collide at any time. The Iridium orbit, for instance is now polluted with a lot of debris that makes additional collisions more likely. The idea of a runaway chain reaction of increasing debris doesn’t seem very far fetched.

The Map Room put up a nice slidshow showing the huge growth of the Las Vegas metropolitan area over the last 20 years. What I found most alarming though was that you can actually see the water level declining in Lake Meade as the city grows.

Granted, I’m not sure if this is just an effect of the images being from different times of year, but alarming nonetheless.

A project has been set up which monitors the astrometry tag on flickr and hashes photos to determine what in the sky is being looked at. Not only does it add annotations for notable objects to the photo, it will allow compilation of a growing set of located images. Apparently a rotation invariant hashing algorithm was used. This essentially means that the image is converted into a hash code, that will be the same no matter what rotation the image was taken in.

Neat stuff. Via slashdot.

From Wired:
“… at precisely 3:31:30 p.m. Pacific time on February 13, 2009, the 10-digit “epoch time” clock used by most Unix computers will display all ten decimal digits in sequence.”
1234567890 seconds since the epoch start.

If you have python installed you can see this by opening the idle shell (in start menu) and typing this:

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import time
int(time.time())  #will display seconds since epoch

Or you could have it print a message at the appropriate moment so you don’t miss it (if that’s important to you :) :

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def check_time(thetime):
   now = int(time.time())
   if now == thetime:
       print 50*'-'
       print 'time is',now,'!'
       print 50*'-'
 
while True:
   check_time(1234567890)

How do you know the relative weight of a scientific paper?  Is it well respected in the field?  Often Cited?  Maslov and Redner discuss the Promise and Pitfalls of Extending Google’s PageRank Algorithm to Citation Networks.  Interestingly, of the top 10 papers by pagerank, 9 are by Nobel Prize winners.