Numerical implementations

[NicolaB]

We take for granted many calculations in every field, everyday, like they're some sort of constant, of standard pratice. In real life, it always boggled me how many different implementations are there and how those different implementations lead to very different results. Just like Matlab in the early 2000s had huge precision problems with simple matrix calculations(we're not talking about edge cases), but nobody rechecked any calculation. "I used program X to do Y, that is the result therefore it must be correct.I didn't check how X does Y". Even engineers rarely care these days.

For example, with signals we usually take resampling for granted and never ask which algorithm is used, or worse, we botch up two lines that will apparently do the job and call it a day. Here is a comparison of very common audio resampling algorithms, where the differences are quite visibile:
https://src.infinitewave.ca/

As another example, when we buy an music album from our favourite artist we never ask ourselves if that editions has a numerical loss of music data and a terrible dynamic range:
https://dr.loudness-war.info/