Search found 69 matches

by Olf
Thu 16 May 2013, 06:59
Forum: Usage
Topic: Help about design of "special" geometry
Replies: 3
Views: 5358

Re: Help about design of "special" geometry

In cartesian coordinates you could also use a rotational polygon: http://openems.de/index.php/Polygon#Rotational_Polygon
I guess in this case a cylindrical coordinate system is really the best.

Regards,
Olf
by Olf
Tue 30 Apr 2013, 10:34
Forum: Usage
Topic: Drude- Lorentz Materials
Replies: 22
Views: 33909

Re: Drude- Lorentz Materials

If you wanna be really fancy, it should be possible to save the permittivity data in a database and then fit each time for the requested frequency range. If the fitting function starts with reasonable (wide band) values it should be possible to get good results every time. I only know for optics, th...
by Olf
Tue 30 Apr 2013, 08:48
Forum: Usage
Topic: openEMS & MPI
Replies: 15
Views: 19812

Re: openEMS & MPI

Thanks for the comment, I was about to do that for a TFSF of about 3 lambda. I better check this on some known case before continuing down this road... Does a finer mesh help at all to improve the accuracy? So in case I want to know a larger frequency range I should run several simulations with adju...
by Olf
Tue 30 Apr 2013, 01:38
Forum: Usage
Topic: openEMS & MPI
Replies: 15
Views: 19812

Re: openEMS & MPI

Ah I see, well that's [scattered filed/total field -> nf2ff] what I wanted do... Well, that's not a problem actually, I just change my strategy. I'll figure out how large structures I'll be able to simulate and for the rest I just start several jobs parallel :)
Cheers,
Olf
by Olf
Mon 29 Apr 2013, 03:36
Forum: Usage
Topic: openEMS & MPI
Replies: 15
Views: 19812

Re: openEMS & MPI

Hi guys, thanks for the replies! I actually want to run both FDTD and NF2FF on the cluster so I guess it would be the easiest to just run the whole script there. ALso then I can just let things run over night or over the weekend :) I'll try to use MPI and see how it goes. I am a bit confused because...
by Olf
Mon 29 Apr 2013, 03:28
Forum: Usage
Topic: Drude- Lorentz Materials
Replies: 22
Views: 33909

Re: Drude- Lorentz Materials

I think GetOpticalMatData would be a bit misleading as most of the materials cover ranges to frequencies much lower than optical (eg. Be, Cr go down to THz). Also I think it would be better to keep only one function for all materials (keep it simple)... How about using two names like <material>_opt ...
by Olf
Fri 26 Apr 2013, 10:08
Forum: Usage
Topic: openEMS & MPI
Replies: 15
Views: 19812

Re: openEMS & MPI

Hi, The cluster is an HPC (SUSE Linux Enterprise Server 11 (x86_64)). I currently start the simulations directly on the machines (using ssh & putty). I always need to do both FDTD + NF2FF, so I am not sure if that is easily possible with the remote ssh method. It is already about three times faster ...
by Olf
Fri 26 Apr 2013, 08:09
Forum: Usage
Topic: openEMS & MPI
Replies: 15
Views: 19812

openEMS & MPI

Hi,
Is there any example how to use openEMS with MPI? I would like to do some simulations on a linux cluster but don't quite understand how to do that from the matlab help...
Any example or explanation would be greatly appreciated :)
Olf
by Olf
Tue 23 Apr 2013, 11:23
Forum: Usage
Topic: Drude- Lorentz Materials
Replies: 22
Views: 33909

Re: Drude- Lorentz Materials

Hi Thorsten, I collected all the parameters from Rakic ea and added some of my own materials. This function creates a material model to use as dispersive material. No guarantee that everything is correct, I have only tested the TiO2. The parameters give the same epsilon as in the publication so I gu...
by Olf
Thu 18 Apr 2013, 09:45
Forum: Usage
Topic: Drude- Lorentz Materials
Replies: 22
Views: 33909

Re: Drude- Lorentz Materials

Just played with the LD parameters, it seems it is difficult to get an exact representation for a large frequency range, at least in the case of TiO2. I fitted the refractive index function for a smaller interval which now gives me nearly perfect agreement between Mie theory and FDTD. It seems small...