On Tue, Apr 05, 2022 at 04:36:24AM +1000, Chris Angelico wrote: > Some unit cancellations really do result in pure scalars. The ratio of > a circle's circumference to its diameter isn't a unit of m/m any more > than the ratio of a circle's area to that of a circumscribed square is > a unit of m²/m². They're both just numbers.
Of course it is a ratio. You said it yourself: it is a ratio of circumference to diameter. That ratio is only numerically equal to π if the units you measure the cicumference and diameter are the same. Otherwise it has units "inches/cm" (or whatever units you used) and a completely different numerical value. > On the other hand, a > radian is a very real unit of distance/distance (based on its > definition of arc length), and it's a unit of angle. The SI system defines both radians and steradians as dimensionless derived units, previously known as "supplementary units". -- Steve _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/PY2SIYNPBLQDRWFLFX6ZL2ZJT77FXMEK/ Code of Conduct: http://python.org/psf/codeofconduct/
