I talked to Ming today, and I finally understand the formulas I'm using. Once I understood, I knew how to devise tests to isolate the problem in my code. The tests works as I expect now, and now I know what to expect. I'd made a type of error that I make often enough: a mishandled boundary case. What surprises me was not the nature of the error, but the fact that it had such subtle and counterintuitive consequences.

The world might be easier if our errors all had immediate and obvious (non-fatal) consequences. It all our errors had immediate fatal consequences, the world would be very quiet.

• Currently drinking: Water