User talk:Kraaiennest/Archive 1

Image Tagging Image:Disp bouss.png

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Thanks for uploading Image:Disp bouss.png. I notice the image page currently doesn't specify who created the content, so the copyright status is unclear. If you have not created this media yourself then you need to argue that we have the right to use the media on Wikimedia Commons (see copyright tagging below). If you have not created the media yourself then you should also specify where you found it, i.e., in most cases link to the website where you got it, and the terms of use for content from that page. If the content is a derivative of a copyrighted work, you need to supply the names and a licence of the original authors as well.

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Please delete, Kraaiennest 12:10, 8 March 2008 (UTC)

Group velocity; File:Wave group.gif

Hi! Your made and up loaded "File:Wave group.gif" (and "File:Wave phase.gif") is very attractive. Could you revise and up load File:Wave group.gif three waves with Wave A and B, and A+B (showing group velocity)having phase velocity red dot on approx. 1Hz current wave (A) and yellow dot on 1/13Hz(?) (B), then show "A+B" on top. Also have green dot and Reticle, with vertical bar over (A) and (B), on group velocity point for more understandable descriptive image. Thank you.--Namazu-tron (talk) 07:10, 23 December 2008 (UTC)

Tip: Categorizing images

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Hello, Kraaiennest!

Tip: Add categories to your files

Thanks a lot for contributing to the Wikimedia Commons! Here's a tip to make your uploads more useful: Why not add some categories to describe them? This will help more people to find and use them.

Here's how:

1) If you're using the UploadWizard, you can add categories to each file when you describe it. Just click "more options" for the file and add the categories which make sense:

2) You can also pick the file from your list of uploads, edit the file description page, and manually add the category code at the end of the page.

[[Category:Category name]]

For example, if you are uploading a diagram showing the orbits of comets, you add the following code:

[[Category:Astronomical diagrams]]

[[Category:Comets]]

This will make the diagram show up in the categories "Astronomical diagrams" and "Comets".

When picking categories, try to choose a specific category ("Astronomical diagrams") over a generic one ("Illustrations").

Thanks again for your uploads! More information about categorization can be found in Commons:Categories, and don't hesitate to leave a note on the help desk.

BotMultichillT 05:55, 12 April 2009 (UTC)

• Image:KdV cubic polynomial.svg is uncategorized since 11 April 2009.

orbital_wave_motion.svg

Hi, not sure I understand the file orbital_wave_motion, could you explain? My notes all report that the motion is clockwise, can you explain why you claim it to be anticlockwise? 86.17.59.23

The motion in File:orbital_wave_motion.svg is "clockwise", if following a single particle in time. The figure however shows a snapshot of the position of the particles at a fixed time. As well as their orbits they make during a wave cycle. -- Crowsnest (talk) 09:44, 16 January 2010 (UTC)

Many thanks for this, understood now. Perhaps you could help me with another question to do with the orbital motion. I have been slightly confused in my background reading, some sources depict particle positions at the quarter phase (half way between crest and trough) as being at the perpendicular position, which is logical in terms of velocity. However, it follows that the particle is no longer at the surface, instead below the surface (the surface coincides with the top left and bottom right of the orbit or vice versa e.g. diagonally). Some sources depict the particle at the diagonal ends of the orbit at this state (e.g. Alonzo, 1972). Perhaps you could point me on the right direction of thinking with this, as it is I am suspecting this discrepancy has something to do with the non-trachoidal assumptions of Airy Wave theory. Liquid121 (talk)

Wave packet propagation in negative index medium

Hello! I was looking through your work, and i saw the Frequency dispersion in bichromatic groups of gravity waves on the surface of deep water. or as the file is called, wavegroup.gif which is your own work! FIrst of all let me congratulate on that! Unfortunately tho, I'm not as good with creating gif's and animations, but I'd need to see or actually create a simulation or animation of a pulse or wavefront travelling through a negative group velocity medium (or negative index medium). Is there any chance you have made one like that, or could you make one and send it to me? Maybe you'd know any links where i can find suck animation? Thank you Zoltan

Hello Zolee86, thank you. What relationship between phase and group velocity are you thinking of? And how many waves should there be in the group? Best regards, Kraaiennest (talk) 20:18, 13 January 2011 (UTC)

PS: You can sign with four tildes (~~~~), which will expand as your user name and date/time.

Was there once an animated gif ...

... of something like this static image: File:Wave_motion-i18n-mod.svg? I used that animation on gewp.org, but it seems to be missing from Commons, now. I see deletions of earlier versions of this file. Was one of the deleted files animated? Or, am I looking in the wrong place? I no longer see any animations on the encyclopedia articles on waves, either. Was there possibly an error by assuming that the trace of a rolling circle is a Sin wave? I might re-do the animation if you are not. I already have code published on the trace of the tips of a Savonius rotor, and that is very similar math. See the top image on the homepage of http://www.youvan.com, and Example 19 please. Thank you, Kraaiennest / Crowsnest Doug youvan (talk) 18:03, 14 January 2012 (UTC)

Hello Doug youvan, my animations at Commons are listed here: [1], which hopefully contains also the one you search. I am not aware of animations being deleted. Regards, Kraaiennest (talk) 22:02, 15 January 2012 (UTC)

Now, I see the word Trochoid in your discussions, above, and tracked it into simple math that I should have known. I will copy this to my own Talk page if you have anything to say. When I was writting code for the Savonius Rotor, I did not know the term "Trochoids". But I did come to the same independent conclusion / math / code. Doug youvan (talk) 01:19, 15 January 2012 (UTC)

Dear Crow, I found a backup of my deleted gewp.org site and the file name. I searched that name on Google and found: http://commons.wikimedia.org/wiki/File:Deep_water_wave.gif . It's usage is on wikis other than in English. Is something like that file currently in use by you anywhere on en. ? Also, would you share that source code with me? I would like to re-write in Mathematica with proper attribution to you. Doug youvan (talk) 16:38, 21 January 2012 (UTC)

Hello Doug Youvan, File:Deep water wave.gif is in use on en-wiki in "Wind wave" and in "Stokes drift". The wave physics are computed with the Rienecker & Fenton (R&F) streamfunction theory; for a computer code to compute these see: J.D. Fenton (1988) "The numerical solution of steady water wave problems". Computers & Geosciences 14(3), pp. 357–368. The animations are made from the R&F results with a series of Matlab scripts and batch files. Regards, Kraaiennest (talk) 21:13, 21 January 2012 (UTC)

Dear Crow, Thanks for all that information. Is there anything you would like to see done in Mathematica from scratch? I would do the coding at your direction. The contribution here to Commons would be done jointly. Links in the description of the image could be made out to Wolfram's CDF player and the actual code could be deposited elsewhere such that anyone could download the CDF Player (free) and adjust parameters within our code. I would suggest re-doing File:Deep water wave.gif so that the new code could be checked. The custom code we deposit (elsewhere) would be freeware. A second possibility is to write code for a parameterized interferometer using this same scenario of an image deposited here on Commons, links to custom freeware, and a link to the CDF Player.

A search for "J D Fenton Ocean Waves" yields many on-line calculators: http://pipeng.com/index.php/ms/keyword/detail/Ocean%20Wave%20:%20Calculator .Doug youvan (talk) 17:12, 22 January 2012 (UTC)

Dear Crow, May I have a copy of the source code that was used to make File:Deep water wave.gif? As you know, I would like to re-do this work in Mathematica and make it public domain, and it would be very nice if this were a joint project between us. In addition to Commons, http://demonstrations.wolfram.com/MotionOfParticlesInOceanWaves/ would be a great place to deposit in Wolfram CDF as an educational game. One could make parameters of amplitude and period of an ocean wave and make a game of a Stokes Ball Race! Someone else has already deposited a Rogue Wave simulation. Doug youvan (talk) 23:31, 30 January 2012 (UTC)

Dear Doug Youvan, I do not intent to make the code available, since it is (in part) the property of others. The code has been extensively validated against the results of similar codes by others. I pointed out before the Fenton paper, which contains a full source code to compute these kinds of waves, which you can use as a basis for your plans. Further, I personally have no interest in joint projects (of code development, Mathematica stuff, animations, etc.). Best regards, Kraaiennest (talk) 01:39, 2 February 2012 (UTC)

Dear Crow, I trust you have seen the level of energy that children place into worthless video games. We really have a chance here to develop something entertaining and educational. Would you at least consider donating code into the Mathematica site I have referenced, above? If needed, I will gladly grant you funds to do so through my Foundation to do the re-coding. I have no other motives other than seeing my son, now age 7, and other children like him, play games that are educational. Consider this an end-of-life, philanthropic goal of mine. I think you know me well enough to understand that I am not playing games (no pun intended) with you. Doug youvan (talk) 03:47, 2 February 2012 (UTC)

FYI, I have begun emailing people in your field in an attempt to find your colleagues who did this programming. I am now of the opinion that it is the programmers, not the uploader of this work, who should be cited as authors. That's still another reason for you and I to re-do the code and place it in the public domain: The authorship would be clean and clear. Doug youvan (talk) 00:35, 4 February 2012 (UTC)

Hello Doug, good luck and fun with your project! Regards, Kraaiennest (talk) 14:25, 5 February 2012 (UTC)

Hi Kraaiennest; I don't see that you were notified of a Village Pump discussion that may involve you. --Walter Siegmund (talk) 17:37, 6 February 2012 (UTC)

Yes Crow, Please join us. If you are candid and honest, the WMF gets $100,000! Doug youvan (talk) 03:24, 7 February 2012 (UTC)

I went back down to $10K and placed an image of the cashiers check in that discussion. I am also transplanting this statement you made: "Dear Doug Youvan, I do not intent to make the code available, since it is (in part) the property of others." Doug youvan (talk) 16:02, 7 February 2012 (UTC)

File:Bous2d berk03 z.gif

Ontzettend bedankt voor deze! Erg nuttig voor colleges over golven en optica. Groeten, /Pieter Kuiper (talk) 09:58, 8 February 2012 (UTC)

Dank je wel! -- Kraaiennest (talk) 10:02, 8 February 2012 (UTC)

I agree with Pieter Kuiper. That is a educational and pleasing animation.

I added the patrol right to your account.[2] --Walter Siegmund (talk) 21:47, 8 February 2012 (UTC)

Thank you very much, Walter! Best regards, Kraaiennest (talk) 17:12, 9 February 2012 (UTC)

Pseudocolored Deep Water Wave

Dear Crow, Could you write down an equation for me that would describe every pixel in a deep water wave as a function of our display coordinates, amplitude, period, and time (x,y,A,P,t)? I would like to try an orthonormal 3-axis (120 degree) pseudocoloring scheme to indicate velocity (speed s, direction d) of each pixel. Get it?

You don't have to worry about this part, but I will use a 0-1 color scaling for RGB:

v=0: Black {0,0,0};

maximum velocity up: Red (r,0,0};

maximum velocity towards 120 degrees: Green {0,g,0};

maximum velocity towards 240 degrees: Blue {0,0,b}.

Little r,g,b will be scaled for maximum velocity in any direction, and then all pixel velocity will be projected onto this tri-color-axis. For example, velocity in the direction of 60 degrees will be colored Yellow, 180 is Cyan, and 300 is Magenta. All 360 degrees get a different color by an algorithm and the intensity of those colors is proportional to speed. For each frame, I will pseudocolor for how the pixels will move into the next frame.

Thanks, Doug youvan (talk) 01:29, 9 February 2012 (UTC)

Hello Doug, as already stated before, I am not going to participate in your project. -- Kraaiennest (talk) 20:18, 9 February 2012 (UTC)

AN/U

I've started a discussion on COM:AN/U that mentions you.[3] Your comments are welcome. --Walter Siegmund (talk) 20:30, 9 February 2012 (UTC)

Thanks for informing me. I see he already has been blocked [4]. Best regards, Kraaiennest (talk) 20:38, 9 February 2012 (UTC)

License review

Hallo Kraaiennest, if you upload files from somewhere else in the internet please always request license review like someone else did here. That saves your uploaded file in case the license at flickr is changed in the future. Cheers --Saibo (Δ) 22:45, 15 March 2012 (UTC)

Hi Saibo, thanks for pointing out! So I learned something today :-) Kind regards, Kraaiennest (talk) 23:44, 15 March 2012 (UTC)

User talk:Doug youvan

I just want to inform you that this user, even though he has given you a lot of problems in the past, has passed away. User:Zscout370 ^{(Return fire)} 18:35, 29 May 2012 (UTC)

I think he didn't, but there are some issues just came up that I strongly advise you to email me over. User:Zscout370 ^{(Return fire)} 06:47, 11 June 2012 (UTC)

A barnstar for you!

	The Photographer's Barnstar
	Hello Kraaiennest, I have seen wour animation of the path of a massless particles on a wave. I am looking for some background theory for the behaviour of bodies (with a non negligible mass). Basically I am looking for the conditions for take-off on a wave. Any idea? Pirouette.cacahute (talk) 16:36, 11 January 2013 (UTC)

ArchiveBot

Hi, I noticed you have set up User:MiszaBot to archive your talk page. Unfortunately, the bot has stopped working, and given how its operator is inactive, it is unclear when/if this will fixed. For the time being, I have volunteered to operate a MiszaBot clone (running the exact same code). With that said, your input would be appreciated at Commons:Bots/Requests/ArchiveBot 1. Regards, FASTILY 07:39, 20 April 2014 (UTC)

Flow over airfoil

Thanks for posting the beautiful simulation https://en.wikipedia.org/wiki/Lift_%28force%29#/media/File:Karman_trefftz.gif . If I understand it, air is modeled as quite compressible here. If you did the simulation, can we see one with incompressible liquid?

--Hess88 (talk) 19:21, 25 May 2016 (UTC)

Hello Hess88, the flow is already incompressible (and irrotational), see Kármán–Trefftz transform. Best regards, Crowsnest (talk) 20:08, 28 May 2016 (UTC)

Need help with dispersion plots

Extremely useful

Your plot of Linear phase speed squared c2/(gh) as a function of relative wave number kh is very useful. I can also see that you used MATLAB for generating the said plot. I have been studying linear and nonlinear waves and I was wondering if you could share your source code used for generating the plot with me? If you can do so, it'll be very helpful to me. Vivekfrancis139 (talk) 10:10, 22 June 2016 (UTC)

Hello Vivekfrancis139, thank you. Which plot are you referring to? Can you give a link to it? Best regards, Kraaiennest (talk) 19:44, 26 June 2016 (UTC).

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Request for source code

@Kraaiennest: Dear Sir,
I saw your file used in Phase_velocity.
Thank you very much for creating the gif file!
What were the mathematical equations you used, and what was the software used to produce the gif file?
Please express more about the created file, and thank you once again.
Regards,
Bkpsusmitaa (talk) 06:17, 25 April 2017 (UTC)

TUSC token 01b17fc5373bb6eea993dc86649366d1

I am now proud owner of a TUSC account! — Preceding unsigned comment added by Kraaiennest (talk • contribs) 14:04, 2 August 2008‎ (UTC)