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#480 by SeeShells on 14 Aug, 2015 12:44
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Dr. Rodal,
For some of the pics there seems to be a weak coupling of TE31 eigenvalue
New png files are uploaded for the 64 cycle Shell 2d loop antenna case. I put up the new csv files as well but they "should" be identical to the previous ones. The png files are named slightly differently than previously so I uploaded them into the existing folders. You won't have any difficulty telling the difference visually, but of course your computer will. I have attached one of the new files here just so all can see the effect of changing the scaling range. And note that the pixel grid separation is exactly the same, 1.1 mm while 1/20th of the length of the frustum is about 12 mm.
Still haven't made your x-30 slice that you asked for a few days ago. Will get it up soon.
https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing
(I get ~2.39GHz for TE311 and ~2.63GHz for TE312, hope i didn't make a mistake! p=1 and p=2 are very close... Rechecked numbers are welcome).
Most interesting is that the whole run looks like coupling to different modes at different time steps inclusive target mode TE012 (TE31p,TM112?)
Yes! Great observation. This is another reason I want to excite in the TE012 mode! We've got something like 5 modes through that frequency spread around 2.45GHz... TE312, TE212, TE411, TE311, TE012. Hard to read the chart unless you sharpen the image.
This is the one difference between a circular waveguide and a conical frustum is the excited modes coupling effects causing mode switching and the mode shifting and decaying into the small end (seen the reverse also happen but because it was at the start of some of the meep multicolor flashing Tie-dyed runs a couple months ago they could be in question).
Shell
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#481 by X_RaY on 14 Aug, 2015 13:00
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TE 114 is also nearby. Mode superposition/competition(/degenerative mode shape) could lead to interesting effects.Dr. Rodal,
For some of the pics there seems to be a weak coupling of TE31 eigenvalue
New png files are uploaded for the 64 cycle Shell 2d loop antenna case. I put up the new csv files as well but they "should" be identical to the previous ones. The png files are named slightly differently than previously so I uploaded them into the existing folders. You won't have any difficulty telling the difference visually, but of course your computer will. I have attached one of the new files here just so all can see the effect of changing the scaling range. And note that the pixel grid separation is exactly the same, 1.1 mm while 1/20th of the length of the frustum is about 12 mm.
Still haven't made your x-30 slice that you asked for a few days ago. Will get it up soon.
https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing
(I get ~2.39GHz for TE311 and ~2.63GHz for TE312, hope i didn't make a mistake! p=1 and p=2 are very close... Rechecked numbers are welcome).
Most interesting is that the whole run looks like coupling to different modes at different time steps inclusive target mode TE012 (TE31p,TM112?)
Yes! Great observation. This is another reason I want to excite in the TE012 mode! We've got something like 5 modes through that frequency spread around 2.45GHz... TE312, TE212, TE411, TE311, TE012. Hard to read the chart unless you sharpen the image.
This is the one difference between a circular waveguide and a conical frustum is the excited modes coupling effects causing mode switching and the mode shifting and decaying into the small end (seen the reverse also happen but because it was at the start of some of the meep multicolor flashing Tie-dyed runs a couple months ago they could be in question).
Shell
The later interpretation don't will be easier with such complex EM messy mix.
All here lurking for your experimental data
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#482 by Rodal on 14 Aug, 2015 13:10
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Here are the last 14 time step images for the Poynting vector field distribution through the trapezium plane with normal y of the Yang/Shell 6 degree cone angle truncated cone, excited with 2 parallel dipole antennas located near the Small Base.
There is a strong Poynting vector oriented from the big base (at the bottom of the images) to the small base (at the top of the images).
__________________________________________________________________
__________________________________________________________________
Meep data (reproduced from aero's file)
Yang-Shell model - 64 cycle run
SeeShell's conic frustum model using 2 parallel dipoles, 0.55 wavelength from and parallel to the small end, 0.9 wavelength long and 1 wavelength apart. Centrally located with middle at axis of asy-symmetry of cone.
z axis = axis of axy-symmetry
(set! fsi 2.45E+009 ) ; Drive frequency, in SI units, Hz.
(set! bigdia 0.201) ; ID - In meters [CORRECTED from original erroneous file]
(set! bigrad (/ bigdia 2))
(set! smalldia 0.1492) ; ID - meters [CORRECTED from original erroneous file]
(set! smallrad (/ smalldia 2))
(set! high 0.24) ; Inner length, meters [CORRECTED from original erroneous file]
Source excitation magnetic component Hz.
Run length - 64 full cycles
Time slices output for each field component:
every 1/10-th cycle from 62.7 cycles to 64 cycles (end of run)
run time set to 26.104377295238095 meep time set [CORRECTED from original erroneous file]
run 0 finished at t = 26.106 (13053 timesteps) [CORRECTED from original erroneous file]
Resolution = 250
230x196x196x14 is .h5 files dimensions.
End cuts are at: Big end -- .h5 row 15 Small end -- .h5 row 214
Note: Resonant frequency calculated by meep is 2.463GHz
NSF handle_aero__ Date of upload. 8/6/2015
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#483 by SeeShells on 14 Aug, 2015 13:12
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I still need to build a couple of stands yet, the materials that were going to be picked up yesterday by a friend with a truck didn't make it. He was worried that the heavy rains we had would ruin the melamine sheets, he was right. Getting them today and will start putting together the stands for the graph-stand and the digital scales. Still waiting for some hardware to get here from China... It has to be on a slow boat.
TE 114 is also nearby. Mode superposition/competition could lead to interesting effects.Dr. Rodal,
For some of the pics there seems to be a weak coupling of TE31 eigenvalue
New png files are uploaded for the 64 cycle Shell 2d loop antenna case. I put up the new csv files as well but they "should" be identical to the previous ones. The png files are named slightly differently than previously so I uploaded them into the existing folders. You won't have any difficulty telling the difference visually, but of course your computer will. I have attached one of the new files here just so all can see the effect of changing the scaling range. And note that the pixel grid separation is exactly the same, 1.1 mm while 1/20th of the length of the frustum is about 12 mm.
Still haven't made your x-30 slice that you asked for a few days ago. Will get it up soon.
https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing
(I get ~2.39GHz for TE311 and ~2.63GHz for TE312, hope i didn't make a mistake! p=1 and p=2 are very close... Rechecked numbers are welcome).
Most interesting is that the whole run looks like coupling to different modes at different time steps inclusive target mode TE012 (TE31p,TM112?)
Yes! Great observation. This is another reason I want to excite in the TE012 mode! We've got something like 5 modes through that frequency spread around 2.45GHz... TE312, TE212, TE411, TE311, TE012. Hard to read the chart unless you sharpen the image.
This is the one difference between a circular waveguide and a conical frustum is the excited modes coupling effects causing mode switching and the mode shifting and decaying into the small end (seen the reverse also happen but because it was at the start of some of the meep multicolor flashing Tie-dyed runs a couple months ago they could be in question).
Shell
The later interpretation don't will be easier with such complex EM messy mix.
All here lurking for your experimental data
I'm pushing as hard as I can as I want it too!
Shell -
#484 by SeeShells on 14 Aug, 2015 13:26
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Nice Poynting show to small end.
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#485 by X_RaY on 14 Aug, 2015 13:27
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Here are the last 14 time step images for the Poynting vector field distribution through the trapezium plane with normal y of the Yang/Shell 6 degree cone angle truncated cone, excited with a 2 parallel dipole antennas near the Small Base.
Interesting! Looks like strong vector component always into the direction of the small diameter..
There is a strong Poynting vector oriented from the big base (at the bottom of the images) to the small base (at the top of the images).
__________________________________________________________________
Meep data
Yang-Shell model - 64 cycle run
SeeShell's conic frustum model using 2 parallel dipoles, 0.55 wavelength from and parallel to the small end, 0.9 wavelength long and 1 wavelength apart. Centrally located with middle at axis of asy-symmetry of cone.
z axis = axis of axy-symmetry
(set! fsi 2.45E+009 ) ; Drive frequency, in SI units, Hz.
(set! bigdia 11.01) ; ID - inches
(set! smalldia 6.25) ; ID - inches
(set! high 10.2) ; length - inches
Source excitation magnetic component Hz.
Run length - 64 full cycles
Time slices output for each field component:
every 1/10-th cycle from 62.7 cycles to 64 cycles (end of run)
run 0 finished at t = 13.054 (6527 timesteps) - Resolution = 250
230x196x196x14 is .h5 files dimensions.
End cuts are at: Big end -- .h5 row 15 Small end -- .h5 row 214
Note: Resonant frequency calculated by meep is 2.463GHz
NSF handle_aero__ Date of upload. 8/6/2015
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#486 by rfmwguy on 14 Aug, 2015 13:31
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Thanks DM, I immediately thought of you when he mentioned how skeptics and believers got along so well here. I tried to say that it was a productive thing to have that occur...with civility. Yes,were are some things he talked about before I came on that would question, but its show biz and gets people wondering...
I was pleasantly surprised at how concisely and accurately Hoagland could express himself when he wanted to. He'd obviously done a fair bit of research on the topic and had his duckies in a row there. All the more cognitively dissonant, therefore, when he claims he sees artificial structures on practically every body in the solar systemI'm more concerned abt getting the word out abt serious work, pro and con, on this global project...outside the veil of corporate and government secrecy. Internet collaboration is what makes this different from most efforts. Want to emphasize that to whomever will listen.
Hoagland! Boy you walked into that one!
But actually he was pretty good at helping to describe the em drive. Very interesting show! Hope you decide to go back on Dave! Nice radio voice too! 
Have been intrigued by this topic, but was daunted by trying to wade through all 4 threads. The show was an excellent introduction.
Am dismayed by the apparent lack of theory about how or why this thing works, if it does. I'm reminded of the difference between Edison and Tesla. Edison was the tinkerer who didn't really understand what he was doing, and didn't really care as long as the invention worked. Tesla, on the other hand was the theoretician who was able to progress by leaps and bounds on the basis of his (mostly) sound understanding of the theory.
What do you guys think?
.
I'm glad Dave made the point that there isn't one theory that explains EmDrive - I believe that to be a fair representation of the situation. As for the convection issue - well, let's just say it might be problematic, but let's wait and see what the data says.
All in all, it was as expected...fun. Actually the 2 hours seemed to fly by. I knew this was the first radio chat about the emdrive, so I tried to keep it as general as I could. Thanks for the comments and for staying up late
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#487 by teitur on 14 Aug, 2015 13:45
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Thanks DM, I immediately thought of you when he mentioned how skeptics and believers got along so well here. I tried to say that it was a productive thing to have that occur...with civility. Yes,were are some things he talked about before I came on that would question, but its show biz and gets people wondering...
I was pleasantly surprised at how concisely and accurately Hoagland could express himself when he wanted to. He'd obviously done a fair bit of research on the topic and had his duckies in a row there. All the more cognitively dissonant, therefore, when he claims he sees artificial structures on practically every body in the solar systemI'm more concerned abt getting the word out abt serious work, pro and con, on this global project...outside the veil of corporate and government secrecy. Internet collaboration is what makes this different from most efforts. Want to emphasize that to whomever will listen.
Hoagland! Boy you walked into that one! But actually he was pretty good at helping to describe the em drive. Very interesting show! Hope you decide to go back on Dave! Nice radio voice too!
Have been intrigued by this topic, but was daunted by trying to wade through all 4 threads. The show was an excellent introduction.
Am dismayed by the apparent lack of theory about how or why this thing works, if it does. I'm reminded of the difference between Edison and Tesla. Edison was the tinkerer who didn't really understand what he was doing, and didn't really care as long as the invention worked. Tesla, on the other hand was the theoretician who was able to progress by leaps and bounds on the basis of his (mostly) sound understanding of the theory.
What do you guys think?.
I'm glad Dave made the point that there isn't one theory that explains EmDrive - I believe that to be a fair representation of the situation. As for the convection issue - well, let's just say it might be problematic, but let's wait and see what the data says.
All in all, it was as expected...fun. Actually the 2 hours seemed to fly by. I knew this was the first radio chat about the emdrive, so I tried to keep it as general as I could. Thanks for the comments and for staying up late
It would be very nice if it was possible to download a podcast or get a link so we who couldn't listen live also could hear it.
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#488 by lmbfan on 14 Aug, 2015 14:13
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Dr. Rodal,
I generated and uploaded a z-30 slice to 64 cycle Shell-2D-loop-ant, z-30-csvs and z-30-pngs. Your current link should work so tell me if it doesn't.
I want to thank Imbfan for all of the hard work of automating the generation of these files. I don't think it could have been done manually. Thank you Imbfan.
aero
You're very welcome. I'm glad I could help! I'll post up the modified python file for others once I make a few more tweaks. -
#489 by Warren Platts on 14 Aug, 2015 14:19
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It would be very nice if it was possible to download a podcast or get a link so we who couldn't listen live also could hear it.
THey MIGHT replay it later today, before the regular programming restarts at 4PM EDT; otherwise you have gto pay $5/month to have unlimited podcast access.
http://player.streamguys.com/dmr/sgplayer/player.php
ETA: That was funny when Hoagland said he tried to register at NSF and found out he was already pre-banned!
Come on Chris! Give the man a break! Surely the NSF tent is big enough for everybody! I must say I've never heard anyone else on the radio give so much airtime to NSF! Only good things to say too!
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#490 by rfmwguy on 14 Aug, 2015 14:22
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Looks like all shows are digitally archived and can be listened to anytime. Think you have to sign up for access. Not sure the procedure but you might try here: http://darkmatterdigitalnetwork.com/shows/other-side-of-midnight/
Thanks DM, I immediately thought of you when he mentioned how skeptics and believers got along so well here. I tried to say that it was a productive thing to have that occur...with civility. Yes,were are some things he talked about before I came on that would question, but its show biz and gets people wondering...
I was pleasantly surprised at how concisely and accurately Hoagland could express himself when he wanted to. He'd obviously done a fair bit of research on the topic and had his duckies in a row there. All the more cognitively dissonant, therefore, when he claims he sees artificial structures on practically every body in the solar systemI'm more concerned abt getting the word out abt serious work, pro and con, on this global project...outside the veil of corporate and government secrecy. Internet collaboration is what makes this different from most efforts. Want to emphasize that to whomever will listen.
Hoagland! Boy you walked into that one! But actually he was pretty good at helping to describe the em drive. Very interesting show! Hope you decide to go back on Dave! Nice radio voice too!
Have been intrigued by this topic, but was daunted by trying to wade through all 4 threads. The show was an excellent introduction.
Am dismayed by the apparent lack of theory about how or why this thing works, if it does. I'm reminded of the difference between Edison and Tesla. Edison was the tinkerer who didn't really understand what he was doing, and didn't really care as long as the invention worked. Tesla, on the other hand was the theoretician who was able to progress by leaps and bounds on the basis of his (mostly) sound understanding of the theory.
What do you guys think?.
I'm glad Dave made the point that there isn't one theory that explains EmDrive - I believe that to be a fair representation of the situation. As for the convection issue - well, let's just say it might be problematic, but let's wait and see what the data says.
All in all, it was as expected...fun. Actually the 2 hours seemed to fly by. I knew this was the first radio chat about the emdrive, so I tried to keep it as general as I could. Thanks for the comments and for staying up late
It would be very nice if it was possible to download a podcast or get a link so we who couldn't listen live also could hear it. -
#491 by Ricvil on 14 Aug, 2015 14:29
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http://math.mit.edu/~stevenj/papers/JohnsonBi02.pdf
The math behind.
Wow this is like a mishmash of @Notsosureofit and @Mike McCulloch. It even has a tapered waveguide. Very excited to read this closely later.
http://arxiv.org/abs/physics/0606072
Yes, that's exactly (same equations) how I'm trying to work out the entropy. -
#492 by teitur on 14 Aug, 2015 14:37
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Looks like all shows are digitally archived and can be listened to anytime. Think you have to sign up for access. Not sure the procedure but you might try here: http://darkmatterdigitalnetwork.com/shows/other-side-of-midnight/
Got it ! Thanks a lot. (Now to find out how to unsubscribe )
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#493 by aero on 14 Aug, 2015 15:29
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Here are the last 14 time step images for the Poynting vector field distribution through the trapezium plane with normal y of the Yang/Shell 6 degree cone angle truncated cone, excited with 2 parallel dipole antennas located near the Small Base.
There is a strong Poynting vector oriented from the big base (at the bottom of the images) to the small base (at the top of the images).
__________________________________________________________________
Meep data (reproduced from aero's file)
Yang-Shell model - 64 cycle run
SeeShell's conic frustum model using 2 parallel dipoles, 0.55 wavelength from and parallel to the small end, 0.9 wavelength long and 1 wavelength apart. Centrally located with middle at axis of asy-symmetry of cone.
z axis = axis of axy-symmetry
(set! fsi 2.45E+009 ) ; Drive frequency, in SI units, Hz.
(set! bigdia 11.01) ; ID - inches
(set! smalldia 6.25) ; ID - inches
(set! high 10.2) ; length - inches
Source excitation magnetic component Hz.
Run length - 64 full cycles
Time slices output for each field component:
every 1/10-th cycle from 62.7 cycles to 64 cycles (end of run)
run 0 finished at t = 13.054 (6527 timesteps) - Resolution = 250
230x196x196x14 is .h5 files dimensions.
End cuts are at: Big end -- .h5 row 15 Small end -- .h5 row 214
Note: Resonant frequency calculated by meep is 2.463GHz
NSF handle_aero__ Date of upload. 8/6/2015
Thanks for posting that information - I see that I didn't edit the dimensions. Those are NSF-1701(I have edited now). The correct cavity dimensions for the Yang-Shell model are:
(set! bigdia 0.201) ; ID - In meters
(set! bigrad (/ bigdia 2))
(set! smalldia 0.1492) ; ID - meters
(set! smallrad (/ smalldia 2))
(set! high 0.24) ; Inner length, meters
I try, but there are a lot of fiddly-bits to keep track of. -
#494 by rfmwguy on 14 Aug, 2015 15:50
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Boom! We've got a good lead here imho...math.mit.edu/~stevenj/papers/JohnsonBi02.pdf
The math behind.
Wow this is like a mishmash of @Notsosureofit and @Mike McCulloch. It even has a tapered waveguide. Very excited to read this closely later.
http://arxiv.org/abs/physics/0606072
Yes, that's exactly (same equations) how I'm trying to work out the entropy.
Wow. That is a really great paper. A goldmine. Thanks for posting the link -
#495 by aero on 14 Aug, 2015 16:08
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Dr. Rodal:
Regarding your concern that the view files seem to be incorrect. We must be more specific because it is not a meep problem. The view png files are generated as follows:
- meep, using the supplied control file, propagates the EM fields and writes the specified output to .h5 files. Then meep goes away, never to be heard from again.
- h5totxt, a different stand-alone program, reads the .h5 files by specified slice, extracts the maximum and minimum data range (saving it) and writes the slice data to the .csv files which are uploaded.
- h5topng, yet another stand-alone program, using the maximum and minimum data extracted by h5totxt above, reads the h5 files and writes the view .png files of the specified slice which are uploaded.
If it were a meep problem then the .h5 data would be wrong but the csv and png data would be consistent.
If it were an h5totxt problem the data that you generate independently of the csv files would not agree with the csv data?
If it were an h5topng problem the ... well, I think this is the place to start. But where do we start with that?
The first check that I can imagine is to verify that the maximum and minimum values per slice pulled by h5totxt are in fact the same as exist in the csv data that you use.
Another possibility is that the x and y coordinates are reversed in my meep control file but if so, the png views and the csv data should be consistent so I discount that as a source of this particular problem.
Perhaps you or others have some debug suggestions? -
#496 by SeeShells on 14 Aug, 2015 16:15
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Just started reading... wow. I'm going to have to read more later...math.mit.edu/~stevenj/papers/JohnsonBi02.pdf
The math behind.
Wow this is like a mishmash of @Notsosureofit and @Mike McCulloch. It even has a tapered waveguide. Very excited to read this closely later.
http://arxiv.org/abs/physics/0606072
Yes, that's exactly (same equations) how I'm trying to work out the entropy.
Wow. That is a really great paper. A goldmine. Thanks for posting the link -
#497 by WarpTech on 14 Aug, 2015 16:19
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http://math.mit.edu/~stevenj/papers/JohnsonBi02.pdf
The math behind.
Wow this is like a mishmash of @Notsosureofit and @Mike McCulloch. It even has a tapered waveguide. Very excited to read this closely later.
http://arxiv.org/abs/physics/0606072
Yes, that's exactly (same equations) how I'm trying to work out the entropy.
Can't wait to get off work so I can study this baby! Thanks.
Todd
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#498 by Rodal on 14 Aug, 2015 16:43
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Dr. Rodal:
aero,
Regarding your concern that the view files seem to be incorrect. We must be more specific because it is not a meep problem. The view png files are generated as follows:
- meep, using the supplied control file, propagates the EM fields and writes the specified output to .h5 files. Then meep goes away, never to be heard from again.
- h5totxt, a different stand-alone program, reads the .h5 files by specified slice, extracts the maximum and minimum data range (saving it) and writes the slice data to the .csv files which are uploaded.
- h5topng, yet another stand-alone program, using the maximum and minimum data extracted by h5totxt above, reads the h5 files and writes the view .png files of the specified slice which are uploaded.
If it were a meep problem then the .h5 data would be wrong but the csv and png data would be consistent.
If it were an h5totxt problem the data that you generate independently of the csv files would not agree with the csv data?
If it were an h5topng problem the ... well, I think this is the place to start. But where do we start with that?
The first check that I can imagine is to verify that the maximum and minimum values per slice pulled by h5totxt are in fact the same as exist in the csv data that you use.
Another possibility is that the x and y coordinates are reversed in my meep control file but if so, the png views and the csv data should be consistent so I discount that as a source of this particular problem.
Perhaps you or others have some debug suggestions?
Last time I checked this you had the wrong range, which resulted in clipping the images at only 3% of maximum value. That's why there was a problem: it had nothing to do with pixel averaging. It was because the wrong range was used.
The image with a field near zero was being shown with contours and the other fields were clipped at 3% of their maximum value.
In my last message I suggested that you should start by checking your range, and asked what range did you use this time.
What was the range you input this time?
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#499 by flux_capacitor on 14 Aug, 2015 17:39
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A new DIYer is going to resume Iulian Berca's work where it was left, with the same frustum dimensions (the latest one with the cylindrical extension) and same kind of powerful 1100W magnetron.
His nickname is SullyEmDrive on Reddit and he made a great web site:
https://sullyemdrive.wordpress.com
Dimensions of SullyEmDrive's frustum:
Db = 279 mm
Ds = 159 mm
L = 228 mm
cylindrical neck = 76 mm
The small end is tunable with an axial screw so the length between ends is adjustable from 228 to 304 mm.
Unlike Iulian who positioned the waveguide as closely as possible to the big end (see Iulian's diagram) Sully positioned his more near the small end. So at full small-end extension, the waveguide will be roughly in the middle of the two end plates.
He may found resonance at TE013 and TE213 modes for various lengths. Will be interesting to measure the produced force for the two modes and see if the longer frustum length for TE013 is better (as advised by Shawyer) than TM213 mode.
It would be cool is Sully could come here on NSF to share his build, ideas and test results rfmwguy and others already warned him about security so I hope he will stay safe.
But actually he was pretty good at helping to describe the em drive. Very interesting show! Hope you decide to go back on Dave! Nice radio voice too! 
.