R. Clayton (rclayton@clayton.cs.monmouth.edu)
(no date)
I made a mistake when I coded-up draw-tree: I assumed the input to draw-tree
was ordered in the same way with respect to children as is the input to
layout-tree. This is wrong; layout-tree can output nodes in any order it
wants. I didn't catch this error earlier because my implementation of
layout-tree outputs children in the proper order.
The error can be fixed by ordering the nodes at level i by their x coordinate;
however, that assumes the x coordinates are correct (I discovered the problem
when my x-separation testing code failed to flag a bad tree). I need another
fix that doesn't assume the x coordinates are correct, but I can't think of one
right now.
You can also change your implementation of layout-tree to output children in
the proper order, but because problem statement didn't require that, I won't
either.
You should not use draw-tree, or at least not take draw-tree's output
seriously, until I can figure out how to fix it. My apologies to anybody who
spent time trying to correct their program when it may not have been wrong.
This archive was generated by hypermail 2.0b3 on Fri Dec 21 2001 - 17:00:04 EST