topic Re: Interconnected Parameters a=b and b=a in GDL

Interconnected Parameters a=b and b=a

Thomas Nymann — Sun, 25 Aug 2024 22:50:54 GMT

Hi gdl wizards.

Can anybody help create (Parameter) script that will adjust the values in a way that if parameter "xx" changes then parameter "f1" will change accordingly - and then if paramter "f1" changes parameter "xx" will update accordingly.

I know how to do this:

f1=ATN(xx) PARAMETERS f1=f1 xx=TAN(f1) PARAMETERS xx=xx

But in this case "f1" becomes locked!

I need both parameters to be able to control the other one, at any given time!

Hope the information is sufficient enough ‌‌

Cheers

Thomas

Re: Interconnected Parameters a=b and b=a

neilmcallister — Wed, 21 Aug 2024 13:26:00 GMT

If you look at the section titled "Connections between parameters" on this page it should explain how to do it.

https://gdl.graphisoft.com/gdl-basics/parameter-logic

I've not tried it myself, but it looks as though you check the value of GLOB_MODPAR_NAME to see which parameter is being changed and act accordingly. This prevents it getting into a circular loop.

Re: Interconnected Parameters a=b and b=a

Lingwisyer — Thu, 22 Aug 2024 01:22:05 GMT

IF GLOB_MODPAR_NAME = "A" then B = xA PARAMETERS B = B endIF IF GLOB_MODPAR_NAME = "B" then A = B/x PARAMETERS A = A endIF

Re: Interconnected Parameters a=b and b=a

Barry Kelly — Thu, 22 Aug 2024 01:21:30 GMT

Yes GLOB_MODPAR_NAME is your friend here.

I would not use ...

if GLOB_MODPAR_NAME = "xx" then f1 = xx * 2 parameters f1 = f1 else xx = f1 / 2 parameters xx = xx endif

That will work but means if 'xx' is modified,' f1' will update, but if any other parameter is changed 'xx' will be updated.

If you don't want that and only want 'xx' to update when 'f1' is changed then just use separate routines ...

if GLOB_MODPAR_NAME = "xx" then f1 = xx * 2 parameters f1 = f1 endif if GLOB_MODPAR_NAME = "f1" then xx = f1 / 2 parameters xx = xx endif

Barry.

Re: Interconnected Parameters a=b and b=a

Thomas Nymann — Tue, 27 Aug 2024 06:26:07 GMT

Thanks Barry.

That did the trick. Much appreciated 🙂

Re: Interconnected Parameters a=b and b=a

Thomas Nymann — Tue, 27 Aug 2024 06:27:08 GMT

Thanks for that fast reply Lingwisyer. 🙂