Hiya, this is my first post on this site. I am a relative noob to the workings of PD, so prepare for fundamental questions

I am trying to explore additive synthesis, starting with the harmonic series. I understand how the series works, but am not sure how to express it in a function so that the result is the sum of the series limited by the nth value

fund. f number of partials
[440] [n]
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[expr ]
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[osc~]

Another curiosity I have is if I wanted to generate a sawtooth wave this way, is there a way to input infinity into the expression?

Thanks in advance to anyone who can help

from what i heard (by a guy in a pub), you don't NEED to go as far as infinity. you get a pretty good approximation with a limited amount of partials.

i assume you have met the [sinesum] object? this should help you i think

if you input infinity then there will be aliasing. Unless you're going for a specific sound, it's never good to have frequency components higher than the nyquist frequency (1/2 the sample rate). For instance compare a band-limited sawtooth (mmb's got one https://github.com/dotmmb/mmb) to the phasor~ object, which has many harmonics over nyquist. You'll find that the phasor~ sounds much dirtier.

I think the easiest way to do additive synthesis using vanilla is message logic (you could do some list processing) and the "sinesum" or 'cosinesum' method to arrays. I don't have a copy of pd with me but examples of it should be in the help files. You can specify the amplitudes and harmonics directly. As far as equations for fourier series go, check http://en.wikipedia.org/wiki/Fourier_series. there's an equation for sawtooth waves in the middle

Thanks lads. Right off I go to explore these new objects. I kinda figured inputting infinity would crash PD or something alright, was just curious. Cheers for the reply

I shall check out that wiki page too. Wow, 5 years ago I never thought I'd be touching sequnece and series ever again after the Leaving Cert!

I've always wanted to try the sinesum method so I made an abstraction whilst shirking responsibility. Needs ekext for the counter(but any will obviously do)

http://www.pdpatchrepo.info/hurleur/dynsinsum.zip