[army]

Very cool. I think the point about transcribing equations directly from papers glosses over some of the hard issues with building numeric libraries around floating point precision and numeric stability.

It's not that uncommon to see code that would have worked perfectly if double precision floating point numbers were actually real numbers, but which blows up badly once rounding errors happen.

Unfortunately there's not really any way to abstract those issues away. In general, I'd hope that any the authors of widely used numeric libraries have carefully thought through these issues.