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Hello world,
I'm new with COMSOL, and I've some doubts.
My simulation is a 3D Heat Transfer case with a function of position as heat source (the object is a iron cube 1x1x1 m). The heat source function is provided from a file using the Interpolation in the Global definition point in the Model builder tree. The data format is Spreadsheet with 3 arguments and the interpolation is Linear. Its name is DenPot. The file is:
-1 -1 -1 0
-1 -1 1 0
1 -1 -1 0
1 -1 1 0
-1 1 -1 0
-1 1 1 0
1 1 -1 0
1 1 1 0
-0.5 -0.5 0 150
0.5 -0.5 0 1500
-0.5 0.5 0 3500
0.5 0.5 0 2500
-0.5 -0.5 0.5 4150
0.5 -0.5 0.5 500
-0.5 0.5 0.5 2500
0.5 0.5 0.5 5500
Now I can see the 3D Slice of my function DenPot(x,y,z)
In the Heat Source point I have filled the General source field with my function name:

if I write: DenPot
When launch the simulation I get this error:
Failed to evaluate variable Jacobian.
- Variable: DenPot
- Geometry: 1
- Domain: 1
and the simulation is stopped

if I write: DenPot(x,y,z)
When launch the simulation I get the right results (at least I hope so) but if I look in the Heat Source point I see the name of my function in red with the indication: Unexpected unit of input.

Where is the problem?
what is my mistake?

Thanks to all for your attention.
Best regards, Roberto