The width of one sample's interval, or NaN when the chart drew none there.
Read through magnitudeOf rather than Number(point.yMax), which
answers 0 for a null bound -- and JSON carries null wherever
TypeScript says optional. Such a point gets no bound row, no braille cell
and no pitch, so a width measured from it is a number derived from a bound
the chart never drew. NaN minus anything is NaN, which the callers
already discard alongside a wholly absent bound.
The width of one sample's interval, or
NaNwhen the chart drew none there.Read through magnitudeOf rather than
Number(point.yMax), which answers0for anullbound -- and JSON carriesnullwherever TypeScript says optional. Such a point gets no bound row, no braille cell and no pitch, so a width measured from it is a number derived from a bound the chart never drew.NaNminus anything isNaN, which the callers already discard alongside a wholly absent bound.