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hasleytoday at 5:59 AM2 repliesview on HN

I basically agree, at least for standard functions like sin, cos, tan, exp etc. It is even possible to see mistakes in equations just by checking that all the units to standard functions cancel out making the arguments dimensionless.

On the other hand I am still unhappy with calling the ratio of two quantities, that happen to have the same units, "dimensionless". This way, you could create any two "dimensionless" quantities and try to compare them or use one in place of the other which might be meaningless.


Replies

pwdisswordfishqtoday at 10:46 AM

> This way, you could create any two "dimensionless" quantities and try to compare them or use one in place of the other which might be meaningless.

Case in point:

https://trac.ffmpeg.org/ticket/11279

https://trac.ffmpeg.org/ticket/11284

cubefoxtoday at 7:55 AM

Yeah, "dimensionless" would mean they have equal dimension, which would mean they are comparable, which isn't necessarily the case. E.g. both radians and degrees are called "dimensionless".

Edit: Apparently "same dimension" doesn't imply "same unit".