Discussion Forum

Hi Nicholas,

The Application Builder has a functionality called "Record Method" that allows you do perform operations in the COMSOL Desktop and have the software automatically write for you a method that performs those same operations.
Since you no doubt know how to assign the expression length_default to the parameter length in the GUI, just do the following:
In the App Builder, hit the "Record Method" button (A red frame will appear around the interface), go to the Model Builder and there set the Expression for length to length_default, then go back to the App Builder and hit "Stop Recording" (The red frame will disappear).
And there you have it, a method that contains the instruction to set length to length_default!

It typically does not generate the most compact code possible, but it is a convenient tool and a great way to learn some of the syntax and commands.

Hope this helps,
Jeff

Hi Jeff, thanks so much for your quick reply! I have actually done that and written a handful of my own methods to try and solve the problem. The method you described outputs code that looks like:

with(model.param());
set("length", "length_default");
endwith();

This definitely works to set the value of "length" to the value of "length_default" behind the scenes. The problem that I'm having is that I have an input box with "length" as a source and when I run this method, "length_default" will show up in that input box instead of the numerical value that it represents. Furthermore, if I filter that input box to only accept doubles or integers, it will reject the "length_default" string value.

I'm not sure if it's related, but when I update a parameter value in an input box it is updated and I can see that in the plots and solutions however, other parameters don't seem to acknowledge that update. What I mean is that if I update "length" and I have a filter on another input box that has a filter limiting it to a maximum value of "length", it will be limited by the original value and not the updated one. Sorry for rambling, I hope it's just something I'm missing on my end but I think I've been pretty thorough.
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Nick

I think I now see what you mean.
How about this?
with(model.param());
set("length", model.param().evaluate("length_default"));
endwith();

Jeff

Worked like a charm, I really appreciate it!

--
Nick