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Can't use variable defined in 'Global Definitions' within a Waveform definition

Posted 11 nov 2012, 19:41 GMT-5 Version 4.2a 3 Replies

Ben Harrison
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I have defined 'tau' in Global Definitions as a variable = 40000*3600*24*365.25[s]

I have created a Waveform also in Global Definitions (and in local definitions just to check), with angular frequency = 2*pi/tau.
It does not like it: 'Unknown variable name' when I try to plot my Waveform.

If instead I substitute '2*pi/( 40000*3600*24*365.25)', then it's fine.
Why is this?

Ben.
3 Replies Last Post 12 nov 2012, 17:47 GMT-5
Magnus Ringh COMSOL Employee

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Posted: 1 decade ago 12 nov 2012, 04:12 GMT-5
Hi,

You can define 'tau' as a global parameter (Global Definitions>Parameters) instead. The use of variables in function definitions is not supported because in general, variables can depend on time and space variables.

Best regards,
Magnus Ringh, COMSOL
Hi, You can define 'tau' as a global parameter (Global Definitions>Parameters) instead. The use of variables in function definitions is not supported because in general, variables can depend on time and space variables. Best regards, Magnus Ringh, COMSOL
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 12 nov 2012, 14:19 GMT-5
Hi

you can also use better the internal units as you seem to have 40'000 years there and there should be a unit for time in seconds, minutes, hours, days, ... check the doc

--
Good luck
Ivar
Hi you can also use better the internal units as you seem to have 40'000 years there and there should be a unit for time in seconds, minutes, hours, days, ... check the doc -- Good luck Ivar
Ben Harrison
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Posted: 1 decade ago 12 nov 2012, 17:47 GMT-5
Thank you Magnus, I see it now.

Ivar, yes it seems I can enter 40000[yr] instead, thanks.

Ben.
Thank you Magnus, I see it now. Ivar, yes it seems I can enter 40000[yr] instead, thanks. Ben.

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