User talk:LucasVB

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Archive0 (2006-01-24) Archive1 (2012-05-22)

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Surprise, surprise

Parabéns pela animação! Foi uma bela surpresa verificar (a posteriori) que estava a avaliar o trabalho de um conterrâneo! -- Alvesgaspar (talk) 18:23, 14 August 2012 (UTC)

Também achei excelente a animação. Bravo! FilipeS (talk) 14:37, 17 August 2012 (UTC)

Wikipedia:Featured picture candidates/Line integral of scalar field

An image created by you has been promoted to featured picture status Your image, File:Line integral of scalar field.gif, was nominated on Wikipedia:Featured picture candidates, gained a consensus of support, and has been promoted. If you would like to nominate an image, please do so at Wikipedia:Featured picture candidates. Thank you for your contribution! Makeemlighter (talk) 17:23, 26 August 2012 (UTC)

Can you illustrate "covariant derivative"?

I noticed that you have some really great animated illustrations here on Wikipedia. Recently there was a request on Talk:Covariant_derivative#Add_Images requesting some images, and I suggested the following:

I'm not a good graphic artist, but here is a suggestion for a picture. Draw a circle on a flat sheet of paper. Travel around the circle at a constant speed. The derivative of your velocity, your acceleration vector, always points radially inward. Roll this sheet of paper into a cylinder. Now the (Euclidean) derivative of your velocity has a component that sometimes points inward toward the axis of the cylinder depending on whether you're near a solstice or an equinox. This is the (Euclidean) Normal component. The Covariant derivative component is the component parallel to the cylinder's surface, and is the same as that before you rolled the sheet into a cylinder. Cloudswrest (talk) 19:37, 2 January 2013 (UTC)

Math markup errors in Eugenvalues and eigenvectors

Hi,thanks for the note. I did check with preview and did not see THAT many errors. Will check again and fix as appropriate. --Jorge Stolfi (talk) 02:32, 4 February 2013 (UTC)

• I checked again and I did not see ANY serious math markup errors; on the contrary the math displays much better on my browser (Chrome with "render math as SVG" option). What are the errors that you see? --Jorge Stolfi (talk) 02:37, 4 February 2013 (UTC)
• Aha, I switched my Wikipedia preferences to "render as PNG", and now I see the errors you mention. Almost all of them are uses of "×" inside math, in place of \times. The MathJAX renderer understands some of those ISO-latin operator characters, but the Wikipedia server that creates the PNG images apparently doesn't. I will fix them. (By the way, consider using MathJAX with SVG instead of PNGs. It is the way forward it seems...) All the best, --Jorge Stolfi (talk) 02:51, 4 February 2013 (UTC)
• I have fixed the errors with PNG option. Agree that <math>...</math> is too heavy with PNG. See talk page... --Jorge Stolfi (talk) 03:47, 4 February 2013 (UTC)

A barnstar for you!

	The Original Barnstar
	thats some great work Ehypersonic (talk) 13:46, 8 February 2013 (UTC)

Gyro animation

gyro animation

Hello, I've noticed, that the wheel precession directions in the gyro animation created by you are mixed up. They should be swapped to opposite, while keeping the current directions of wheel revolution and the external forces intact.

If you disagree, please take a bike wheel in your hands, start the rotation, apply a force in the same direction as on your animation, and you will see, that the real precession direction is in fact appears to be opposite to what it is on your animation. Atatevyan (talk) 07:47, 9 February 2013 (UTC)

Thanks for the comment. I'll give it a look as soon as I can. — Kieff | Talk 08:57, 9 February 2013 (UTC)

Squaring the circle

Moving the discussion here because Tumblr is an awful medium to have conversations.

So the video is here. I got the ratios and magnitudes (and the idea) from Livio Zucca (he has some other cool math stuff), who was also an avid user of Algodoo (well, back in the days, it was called Phun). The output waveforms from each piston linkage were approximations of sine waves, the magnitudes of which I fudged a bit to make the resulting average as square as possible. I have a few more videos of contraptions made in Phun/Algodoo here (I'll eventually turn them into GIFs). I think you should try out Algodoo. Conundrumer (talk) 21:48, 18 February 2013 (UTC)

Oh, neat! So it's the a Fourier series for the radius based on angle. Pretty close to what I did with those polygons! Algodoo looks pretty cool, thanks for the suggestion.

"What interval would you recommend? Is there a peak activity time where I should aim for?"

I can't say I'm an expert at becoming Tumblr famous, but for now, you should try to maintain a steady stream of content so that people don't forget about you, ie try to publish at least one thing everyday. When you make a lot of content at once, you can put it on queue so the content gets published steadily, instead of all at once. It's okay if you take a break and don't post anything for a period of time, but generally, Tumblr users like to see a variety of content, and seeing a lot of the same kind of posts consecutively wouldn't be as engaging as when the posts are seen individually (well unless they are directly referencing each other, but I guess you can just make a link). If you stick around Tumblr, you can get the feel of the attention span of the typical Tumblr user (not very long!). I hope this helps you gain more presence in Tumblr! ~Conundrumer (talk) 01:58, 20 February 2013 (UTC)

Thanks. I still need to get a feel for tumblr. I barely follow anyone because the rhythm of things seems so incredibly intense and fast. I'm the sort of guy who likes to see everything, so that's a bit of a problem. I'll try to space things out more. Thanks! — Kieff | Talk 02:06, 20 February 2013 (UTC)

What software could you recommend for animated 3D math sketches?

Sir, you are awesome, thanks a lot for your clean and deeply precise animation! Could you recommend some tools for creating animated math sketches like yours? I realize that it depends.

• 3dsMax, Maya, Blender seem to be overhead,
• CLUCalc is nice, but raster,
• to write custom scripts for SVG/pgf/TikZ is to reinvent a wheel.

Mclaudt (talk) 22:49, 24 March 2013 (UTC)

The only one I can recommend is POV-Ray. It's great for technical drawings because you specify everything in terms of code, so it is very precise. The language for describing objects is pretty straightforward, but coding logic on it is a little bit a of a struggle.

But it has no visual feedback until you render things. This may be a problem if you don't have a good spatial intuition. Here's my latest POV-Ray creation, with source code included if you want to try it out. — LucasVB | Talk 22:58, 24 March 2013 (UTC)

Thanks. It's sad that SDL has low abstraction possibilities. I think Mathematica has fantastically flexible and expressive syntax. And some intermediate tool could help develop complex math visualisation. Mclaudt (talk) 06:02, 25 March 2013 (UTC)

Animated sketch for line integral: Hey Lucas, an animation similar to your line integral sketch animation is exactly what we want to do. Nothing like a 3D rendering but an animated sketch, preferably with code-precision. Specifically, what software did you use for making that animation? Thanks!

Math GIFs and Mathematica

Dear Mr. Barbosa,

I am a math teacher in San Diego, CA. I found one of your animated GIFs in an article published yesterday: http://www.businessinsider.com/7-gifs-trigonometry-sine-cosine-2013-5. I am interested in recreating some of your work using Mathematica (or having my students try) and publishing it on the Demonstrations web site (http://demonstrations.wolfram.com/). In particular I love your displays of line integrals and the simple, yet eye-opening illustration of what a radian is.

From what I understand and your copyright label, your work is available for use. If we were to publish work based on your designs, we will give you appropriate credit.

Are you familiar with Mathematica and/or the Demonstrations web site? If not, I believe you would find it fascinating and would be an excellent contributor if you know Mathematica.

Please let me know if you have any objection to me or my students using your work in this way. Thank you.

Sincerely, Abby Brown abby.brown@sduhsd.net — Preceding unsigned comment added by 50.113.98.17 (talk) 00:38, 15 May 2013 (UTC)

Wikipedia:Featured picture candidates/Radian

An image created by you has been promoted to featured picture status Your image, File:Circle radians.gif, was nominated on Wikipedia:Featured picture candidates, gained a consensus of support, and has been promoted. If you would like to nominate an image, please do so at Wikipedia:Featured picture candidates. Thank you for your contribution! Armbrust The Homunculus 16:53, 24 May 2013 (UTC)

animation of paradoxical decomposition

Can I ask your help in creating animation of paradoxical decomposition of the Kelly graph of the free group F_2? I just sow all the beautiful math animation on your page.

I'be created 6 pictures, see [1].

Idealy, the movement of the pieces should be continues, so much more frames should be added. also, in the pass from 3 to 4, one need not only to enlarge the two pieces, but also to add details: the next level of the fractal.

Thank you very much,

Rami (talk) 03:16, 30 May 2013 (UTC)

Sombod offer to help me, so for now, pleas egnor my request

Rami (talk) 03:32, 31 May 2013 (UTC)

Tri-star wheel

A Tri-Star wheel assembly rotating through a hole

If you ever run out of ideas to make cool animations of, consider doing one of the Tri-star (wheel arrangement). I don't know how to make complicated animations. dllu (t,c) 22:16, 1 June 2013 (UTC)

I'm not LucasVB but I can make an animation of this using Algodoo. I'll get back to you in a few days. ~Conundrumer (talk) 04:32, 7 July 2013 (UTC)