ComponentComsol::ElectricField: Field map not yet initialised

[spencer2023]

Hi, I can run the COMSOL examples from garfield++ official website. But then i try to load myself build mesh/field from COMSOL. It failed and with the error as titled.

[mdessole]

Hi @spencer2023,
thanks for reaching out! It is not clear to me whether your issue is ROOT related or not, can you provide a small code snipped of what you’re trying to do?

Cheers,
Monica

[hschindl]

Hi,
there should be some more output from ComponentComsol preceding this error message. Can you post the full log?

[spencer2023]

@hschindl @mdessole
I just try to verify the loading process. See the code as below.

#include

#include

#include

#include <TApplication.h>

#include <TCanvas.h>

#include <TH1F.h>

#include “Garfield/ComponentComsol.hh”

#include “Garfield/ViewField.hh”

#include “Garfield/ViewFEMesh.hh”

#include “Garfield/MediumMagboltz.hh”

#include “Garfield/Sensor.hh”

#include “Garfield/AvalancheMicroscopic.hh”

#include “Garfield/AvalancheMC.hh”

#include “Garfield/Random.hh”

using namespace Garfield;

int main(int argc, char * argv) {

TApplication app(“app”, &argc, argv);

// Load the field map.

ComponentComsol fm;

fm.Initialise(“mesh.mphtxt”, “dielectrics.dat”, “field.txt”, “mm”);

fm.EnableMirrorPeriodicityX();

fm.EnableMirrorPeriodicityY();

fm.PrintRange();

}

Full log:
ComponentComsol::Initialise: 13004 nodes.
ComponentComsol::Initialise:
Error parsing mesh.mphtxt.
ComponentComsol::UpdatePeriodicityCommon:
Field map not yet initialised.
ComponentComsol::UpdatePeriodicityCommon:
Field map not yet initialised.
ComponentComsol::PrintRange:
Dimensions of the elementary block
0 < x < 0 cm,
0 < y < 0 cm,
0 < z < 0 cm,
0 < V < 0 V.
Periodicities
x: mirror with length 0 cm
y: mirror with length 0 cm
z: none

[spencer2023]

I just modified the comsol file of the official example and can make the mesh/field file workable.

By the way, I need to set “relative permittivity” with user defined value, it use “from material”. It will pop out error as below during study computation.

[hschindl]

@spencer2023

ComponentComsol::Initialise: Error parsing mesh.mphtxt.

Looks like ComponentComsol encountered a problem reading your mesh.mphtxt file. Maybe it’s in a different format than the one expected by ComponentComsol (second-order tetrahedra)?

@djjansse have you come across this Comsol error message (“Undefined material property ‘epsilon’ …”)?

[djjansse]

Dear @spencer2023,

On the point of relative permittivity, I believe I have reproduced your case, showing me the same message. You need to provide a relative permittivity to all your materials to be able to solve the system. An example is given in the attached image.

As @hschindl mentioned, the mesh needs to be comprised of second-order tetrahedral elements. Depending on the version of COMSOL you are using, exporting the mesh can be done by right-clicking the mesh object and selecting the export option. Then, you must enable the “export as second-order elements” before writing the .mphtxt file.

I hope this helps.

Kind regards,

Djunes

[spencer2023]

Yes. I did find similar case and follow that instruction. But it does not work.

[spencer2023]

All relative permittivity value have been filled. But not help. Version is 6.2. Build 290