Thursday, January 24, 2013
Well, maybe not quite 3D, but the movie is painted on a globe that you can rotate while it is running.
This is a follow-up to my post yesterday pointing to a new page with NOAA/NCDC SST data displayed on a WebGL globe that you can rotate and zoom.
I have added a movie facility show you can see the dynamics of processes like ENSO. The process works like this. First you select your start date and resolution, as if you were plotting that date. But instead of New Plot, go to the bottom, next to the new Seq button and enter the Step (interval in days) and Number (of frames in the movie).
Then press Seq. This will download the data for the frames. At 1° resolution, this will show as a passable movie, but at 1/4° it will be painfully slow. But let it run. You'll see a pink window just above counting the frames - it will revert to pale green when finished.
Now the payoff - next to the Cyc button you can enter the cycle time for the real movie. For resolution 1/4° you may find that times less than 1 sec will lead to skipping frames; coarser resolutions should do several frames per second (if you really want). Then press Cyc to run the same sequence that you just downloaded, but at the faster speed.
Long sequences at high res will be a load on memory - I estimate about 3-4 Mb per frame. I've been juggling memory vs speed - I can run very fast, but needing 10 Mb per frame.
You can rotate or zoom while the movie is running. You can rerun (Cyc) as you wish. You can go on to do other plots or make more movies, but then you can't rerun the one you had been watching.
I've found that it works as described in Firefox. In Chrome it works, but doesn't show the frames while loading (following Seq) and the red colors don't show to indicate. The movie is OK though. I'm investigating (probably tomorrow).
Where the exact day in sequence is missing, the movie takes the nearest,
It's great for dynamic processes such as ENSO. 1998 is very impressive, even with monthly steps. I'll load more data for this period overnight. I'd recommend starting with low resolution and sequences of 10 frames or so.
Posted by Nick Stokes at 9:56 PM