On Mon, Sep 12, 2011 at 10:38 PM, Shriram Krishnamurthi <s...@cs.brown.edu> wrote: > Time isn't the only measure. And in terms of space, I don't think > you're accounting for all of it.
I don't think either of us is actually accounting for anything, actually. > When you make universe scenes bigger, you tend to see GC pressure. > This *suggests* to me that there is not a lot of sharing from one > display to the next; rather, an entire WIDTHxHEIGHT bitmap is being > generated (and thrown away) each time. Yet I'm pretty certain this is > not how the DOM works. That means the space difference is much more > than the space for representing the circles. That would be a bug (if an entire width*height bitmap were being re-created and thrown away each time and the program was just creating a few circles instead of creating a bitmap of that size). > At least on laptops, increasing the size of the scene seems to induce > more GC, and for large enough images the GC can actually induce a > pause in an animation. I'm pretty sure this is a qualitative > difference between the two models. I think you should measure. A 2htdp/image is just a tree where overlays (and things like that) are interior nodes and leaf nodes are things like circles. Robby _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
