Hi everyone I was wondering how to create a quantizer in pure data, because my intention was to create a modular system in pure data

@t3zeu5 You could use [quantize~] from the zexy library.....
or if your project is not for the audio domain then......... quantize.zip
If you want to do nothing else in Pure Data, and you can run a 32-bit program then you can download Pd-extended from here.......http://puredata.info/downloads/pd-extended

If you want to use a more up-to-date version look to Pd Vanilla..........https://puredata.info/downloads and then use the Help.... Externals..... to "get" the external library.
David.

thank you @whale-av but the quantizer I was intended to create in Pd is more a modular synth like qunatizer where inout MIDI note are put in a precise scale (Dorian, Ionian, etc.).

@t3zeu5 perhaps this abstraction is helpful: https://forum.pdpatchrepo.info/topic/11722/mscale-transpose-notes-according-to-given-scale-and-root there are some other similar abstractions too.

I created a patch that should work but I'm not 100% sure about it
quantizer.pd

@t3zeu5 nice, that should work too. but i would say the mscale abstraction is more flexible because you can change the root note and the length of the scale easily. and the pitch is balanced while your generated pitch is always higher than the original note (if you dont put negative values into the scale).

Interesting. mscale is also not perfectly balanced, as each note in the middle between two notes of the scale will be rounded towards the higher note, similar to what the quantizer does.

With triads, this is only one note, with value 2 (mod 12).

@t3zeu5 Here are two abstractions I made some time ago for that purpose (plus other useful abstractions used in the help files). They suited my needs but can be easily adapted to yours I think. Take a look at f2scale-help.pd and subset-help.pd. Hope this helps.
quantize-abs.zip

thank you very much @weightless but your patches are little bit complex to understand