Re: [Meep-discuss] [Meep discuss] Get the maximum value and another question
Dr. Steven and Ian Buss, Thanks for your explaination on the second question! I am sorry to mispresent my need. What I meant to do in my first question is : How can I get the peak value of the sinusoidal E-field in each unit (The cell), under CW source. 2008/10/30 Steven G. Johnson [EMAIL PROTECTED] On Oct 29, 2008, at 2:15 AM, Yan Liu wrote: 1) How can I get the maximum value of E-field of CW source Analytically, it is impossible in general because it depends on the geometry. (This is a FAQ.) Numerically, obviously you can just output the field and take the maximum. You can also use the built-in max-abs-field-function routine (see the reference manual) to compute the maximum of any arbitrary function of the fields. 2) When I run the time step to 2000, I only want to get the output of 1800-2000. How to deal with it? Use after-time. For example: (run-until 2000 (after-time 1800 output-efield)) ___ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss -- Thanks! Yan Liu Department of Biomedical Engineering, Huazhong University of Science and Technology Phone: (86)-130-7129-6471 Personal Website: sites.google.com/site/yanliurf ___ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
Re: [Meep-discuss] [Meep discuss] Get the maximum value and another question
On Oct 30, 2008, at 5:58 AM, Yan Liu wrote: Dr. Steven and Ian Buss, Thanks for your explaination on the second question! I am sorry to mispresent my need. What I meant to do in my first question is : How can I get the peak value of the sinusoidal E-field in each unit (The cell), under CW source. I'm still not sure I understand your question. You have the electric field E(x,t) as a function of time (t) and space (x) during the simulation. If I understand you correctly, you are asking for the maximum |E(x,t)| over all times t for a fixed position x. Right? If so, I would just recommend the obvious approach of outputting E(x,t) as a function of time and taking the maximum. You can do this by outputting to a file, or you can write a step function that calls get-field-pt at each time step and keeps track of the maximum magnitude. Steven ___ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
[Meep-discuss] [Meep discuss] Get the maximum value and another question
Hi, 1) How can I get the maximum value of E-field of CW source I guess the easiest way is to output efield-X to an hdf5 file and then import it into Matlab (using h5read) or Python (using the 'tables' and 'scipy' modules for example) and do max(array) (in Matlab) where array is the name you gave the data on import. Alternatively, make a definition to call on each time step in Scheme which does the same thing during your simulation (see http://ab-initio.mit.edu/wiki/index.php/Meep_Reference#Writing_your_own_step_functions) . This might be simpler in the long run. Check out the Meep reference though as there might be something that already does this that I have missed. 2) When I run the time step to 2000, I only want to get the output of 1800-2000. How to deal with it? This is actually covered in the Meep tutorial in the Modes of a Ring Resonator example (http://ab-initio.mit.edu/wiki/index.php/Meep_Tutorial#Modes_of_a_ring_resonator ). You just need two run-until loops, e.g: (run-until time1) (run-until time2 (at-every blah blah blah...output-efield-X)) where time1 and time2 are 1800 and 200 iterations in your time units which is determined by your resolution and characteristic lengthscale (if your resolution is 20 say 1 iteration is 0.025 time units, so time1 would be 45). Another option is to enclose your step function in the (after- time ... ) enclosure (documented here: http://ab-initio.mit.edu/wiki/index.php/Meep_Reference#Controlling_when_a_step_function_executes) . Both methods will give you the same thing I believe. Regards, Ian Thanks! -- next part -- An HTML attachment was scrubbed... URL: http://ab-initio.mit.edu/pipermail/meep-discuss/attachments/20081029/40a17c01/attachment-0001.htm -- ___ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss End of meep-discuss Digest, Vol 32, Issue 19 --- Research PhD Student Photonics Group Dept. of Electrical Electrical Engineering University of Bristol Rm 2.11, Queen's Building University Walk Bristol BS8 1TR email: [EMAIL PROTECTED] ___ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
