i 've got some problem to make an abstraction which would smoothly fade from a
reverse sawtooth to a triangle and then to a sawtooth like in some analog synthesizer.
i know the J05.triangle patch but it doesn' t give a very precise shape for the sawtooths form, it' s good for making a triangle wave. usually i use separate oscillator for each waveform but i would like to make a single abstraction. i found a documentation about this subject on this pdf file :

http://www.analoguesystems.co.uk/pdf/RS95-95E.indd.pdf

in fact i' m trying to make a classical shape control

can you help me ?

r_vect1=(p, 1), and r_vect2=(1-p, -1) that will be attached to the first one..

Now just solve: ((0, 0))+a*r_vect1=(x, f(x)) for f(x)
and solve: r_vect1+b*r_vect2=(x, g(x)) for g(x) .
In short get rid of the a and b!
Finally insert this into "OUT".

ps ...man just writing the results would have been faster...

thank you

"If we wish instead to specify the corner location (x, y) (with x in cycles, 0<x<1) we set s = y/x and t = y/(1-x). The DC value is y/2."

You want y to be a constant that is always equal to .5. x is the location of the corner within the cycle. So just plug .5 in for y and use a slider or whatever to change x (making sure it is between 0 and 1), and there you go.

I hope these graphs will help you a little.. ...due to the limitations of painting with letters this example is for a p=0.5...

| / <- f(x) |\ 1_
| / & | \ <- g(x) => | /\ <-min(f(x),g(x))
|/___ x |__\_x |/__\___x
0 1 0 1 0 1

The last graph is the one you want to create, cause if you use a [phasor~]s signal as the x-value you kind of "play" the shape.

indeed my first attempt in J05.triangle.pd was to fix a constant
for up control at 0.5 and to put a slider for down control between à an 1.

x is the position of the peak between the beginning and end of the cycle, and y is the amplitude of that peak. "Up" and "down" refer to the slopes of the triangle wave. You want y to always equal .5, but changing x is going to change both slopes. So, again, looking at the last sentence of the patch:

up = s = .5/x

down = t = .5/(1-x)

in my school there are some users of reaktor and they say to me that what i am looking for is a kind of width control (name in reaktor).

Yeah, Reaktor comes with several pre-made oscillators that just might have a "width" input. In Pd, you have to make it yourself (which is what you're doing here) or find one someone else made. The triangle one is a bit tricky, though.

we can find an illustration of what i am talking about at the end of p.49 and end of p.50 in the pdf that i mentionned in my first post.

I don't know how that oscillator is specifically working, but it looks more like phase distortion. I just recently posted a patch that emulates the Casio CZ oscillators, and the "saw" and "pulse" modes look the ones in that .pdf.

http://puredata.hurleur.com/sujet-6796-casio-oscillators

"If we wish instead to specify the corner location (x, y) (with x in cycles, 0<x<1) we set s = y/x and t = y/(1-x). The DC value is y/2."

i learn a lot by looking on what happen on graph but i can' t manage to write these mathematic equation with pure data object. how can i write these equations with
boxes ? so i understand that x is the position of the corner and y is the amplitude. now if i want to change the position of the peak i need to change the slopes and if i change the slopes the amplitude increase or decrease...
so i tried to change the amplitude of the output of min~ according to the position of the peak in order to avoid low amplitude level. i know it doesn' t do what i want but
i do my best...:(

here the patch

http://www.pdpatchrepo.info/hurleur/J05.triangleGalereWidth.pd

http://www.pdpatchrepo.info/hurleur/j05.trianglepeak.pd

Maelstorm, flipp thank you for your patience !