posted by Robby Findler
As I wondering whether or not there is a better layout algorithm for the module browser window, I looked into tree maps. Of course, the modules in a program form a DAG, not a tree, so I wondered just how big the tree would get if all of the shared structure in the DAG were replicated. Hey, I figured, if a tree map can handle showing me my entire filesystem, maybe that could work.
… yeah, no. Turns out to be hopeless. In the spirit of a geeky take off on a jelly bean counting contest, lets see if you can guess just how big these things get. Consider the module graph from the program
#lang scheme (ie, the graph that just contains an empty program). This program loads 170 modules with 917 connections between modules (counting the main file that just contains the
So, the question: how many nodes are there in the unsharified tree? First one to come within 1 billion of the right answer gets all of the fame and glory that this blog brings to bear (har har). I’ll post the answer in the comments in a few days (and no fair cheating, those of you that know enough to be able to get your hands on the DAG).
Okay, I’ll give it a go on the scale you indicate: … 282 billion? (9^12)
— Kohath, 1 March 2010
Sadly, not close. Lets make this easier. If you’re within a trillion of the correct answer, you win.
— Robby, 2 March 2010
There are 102,295,446,100,979 nodes. Which is a lot. If we somehow used only a single pixel per node (at the standard 72dpi) that would require a monitor that was more that 2 miles square to display the entire thing.
— Robby, 3 March 2010