search

diagrams / diagrams-lib

Diagrams standard library
https://diagrams.github.io/
Other
138 stars 62 forks source link

Attempt to fix issue with trailCrossings #338

Open bacchanalia opened 5 years ago

bacchanalia commented 5 years ago

This is an attempted fix for issue #337. While it gets rid of some instances where test falsely returns a zero value, it is possible it may introduce some instances where test falsely returns a non-zero value.

bacchanalia commented 5 years ago

Some outstanding questions I have relating to this PR: 1) Are there any cases where 1 < t < 1+eps where we actually want to signFromDerivAt to return 0 instead of 1? 2) Are there any cases where -eps < t < 0 where we actually want to signFromDerivAt to return 0 instead of -1? 3) Are the changes form 0 to -eps necessary or are they prevented because of the change in sign? 4) Are we worried about fp error in ang and do should we have eps terms in those comparisons also?