Hi!
From the topic i create about how to copy and paste a mathematic formula in GH, i tried, to do the same for the formula of an elliptic hyperboloid.
But, as i give here the formula, i don’t know, because we have two others parametres: a, and b. And i don’t know how to interprate this.
Other studid question, is, i don’t know how to write the mathematic symbol that we call in french “racine carrée de”, ou “radical de”.
Here i give you the formula.
I don’t know i you have solution. Thanks so much! 
I think the basis is what i did
with the tutorial i did on youtube, but, all the difficultie is in the maner of reinterpreting the formula here!
As I mentioned on your other two threads. Post your file and don’t create 3 threads for nearly the same question.
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Hi Tim! Sorry! Ok! 
Sorry! I m not able to try to write the formula because i don’t know how to write with the computer the symbol “racine carrée” that we have here, as you can see here on the formula i download in jpeg. Can you please help me? Thanks so much!
Thanks so much!
Here, it is the file, i try to do the formula, but it seems i made mistakes.
I know that the z: cv, cu, does’nt have input and output, but i tried to do input, and output, and nothing appears. Here, i have something… but wrong i know.
Other thing is that formula is:
x(u,v)= a squared (1+uu)cos(v)
y(u,v)= b squared (1+uu)sin(v)
z(u,v)= cu
and i don’t know how to “translate” a and b. I dEllipticHyperbol.gh (10.9 KB)
I did like it would be “1”, but shure it’s more complex…
So, thanks so much if you can’t help me! 
sqrt is Square Root, not square. To square something called a you either write a*a, a², a^2 or Pow(a, 2).
If your expression need to access values u, v, and a, then your expression object needs to have those three inputs. You can add (and remove) inputs by zooming in on the expression component and clicking on the (+) signs. You can rename inputs via their context menu. So add a third input called a to your expression, and type:
a * a * (1 + u * u) * Cos(v)
or
a² * (1 + u²) * Cos(v)
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Hi David!
Thanks so much!
The formula, as we can see on my first post here is:
x(u,v)= a squared root of (1+u*u)cos(v)
y(u,v)= b squared root of (1+uu)sin(v)
z(u,v)=cu
Now i m try to do what you say!
Thanks so much!
I didn’t read all the way back to the beginning, I just responded to your last entry which read ‘squared’ not ‘square root’.
The correct GH way of writing the equation from your mathworld screenshot is:
a * Sqrt(1 + u * u) * Cos(v)
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Hi David!
Thanks so much!
Now, i tried to do what i think it was good, but it’s wrong… Here you have the screenshot:
And the new file i modified… but it 's wrong…EllipticHyperbol2.gh (10.2 KB)
Hi David!
thanks so much!
Now i think it’s better… but i think it’s not the result i should have, it’s not an elliptic hyperboloide, and i have only points… but better…
and the new file is here,
Thanks so much! EllipticHyperbol2.gh (10.0 KB)
Why mess around with interpolating points when you can generate a mathematically exact hyperboloid using NURBS? 
Check out this article:
http://www.danieldavis.com/how-to-draw-a-hyperboloid/
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