I have a point in 3D that should move along an elipsis where the lenght of the elipsis should be user specified. I have a time variable that runs from 0.0 -> inf. Any ideas on how I updated the point position on an ellipsis based on this parameter?

0 |

2/28/2009 7:54:15 PM

mlt a �crit : > I have a point in 3D that should move along an elipsis where the lenght > of the elipsis should be user specified. I have a time variable that > runs from 0.0 -> inf. Any ideas on how I updated the point position on > an ellipsis based on this parameter? Hi That's not an OpenGL related question at all, but, if the axis of your ellipsis is oriented according the Ox and Oy axis: x=a.cost y=b.sint where a and b are the half axis. Hope this helps Cathy

0 |

2/28/2009 9:03:29 PM

"Cathy" <no@no.fr> wrote in message news:49a9a6a2$0$25584$426a34cc@news.free.fr... > mlt a �crit : >> I have a point in 3D that should move along an elipsis where the lenght >> of the elipsis should be user specified. I have a time variable that runs >> from 0.0 -> inf. Any ideas on how I updated the point position on an >> ellipsis based on this parameter? > > Hi > That's not an OpenGL related question at all, but, if the axis of your > ellipsis is oriented according the Ox and Oy axis: > x=a.cost > y=b.sint What does "." mean? Is it multiply: x = a*cos(t) ?

0 |

3/1/2009 9:42:39 AM

mlt a �crit : > > "Cathy" <no@no.fr> wrote in message > news:49a9a6a2$0$25584$426a34cc@news.free.fr... >> mlt a �crit : >>> I have a point in 3D that should move along an elipsis where the >>> lenght of the elipsis should be user specified. I have a time >>> variable that runs from 0.0 -> inf. Any ideas on how I updated the >>> point position on an ellipsis based on this parameter? >> >> Hi >> That's not an OpenGL related question at all, but, if the axis of your >> ellipsis is oriented according the Ox and Oy axis: >> x=a.cost >> y=b.sint > > What does "." mean? Is it multiply: > > x = a*cos(t) > > ? Hum... sorry, yes the dot means multiply.

0 |

3/1/2009 4:23:24 PM

Hi there, I am looking for a way to create an oriented tubular structure with an inconstant elliptic cross-section. Practically I want to give as input: -two points, representing the centers of the beginning and ending sections. -major and minor axes of the two extreme ellipses (not only the magnitude of the axes, but also their directions;theoretically the beginning and the ending ellipses could be differently oriented). Could someone give me an help on this topic?Do you consider appropriate using a mesh?Could you explain what I have to do to achieve my aim? I appreciate any help!Thanks in a...

<http://www.ipsnews.net/interna.asp?idnews=26006? .... Go Brazil!!! :-) -- Rick Rick wrote: > <http://www.ipsnews.net/interna.asp?idnews=26006? > > ... Go Brazil!!! :-) The URL above causes a bug in the microshaft web server! :-) Without the last character it works ok http://www.ipsnews.net/interna.asp?idnews=26006 Interesting - Brazil more or less violently commits to OSS with the full force of a government on the offensive liquidating all commercial interests that stand in their way. A model for future governments for steam rolling incompetent IT companies and non...

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Inspiration Information ,----[ Quote ] | Villarreal has access to the Bluestone interview and several others like it | through the Open Source Teaching Project, a Tennessee-based program that | helps students make real-life connections to academic content. The program | sends interviewers to speak faceto- face with experts in a range of fields | who share their passion for their work, explain what they do on a daily | basis, and suggest steps students can take to achieve similar careers. The | interviews are then posted online, free for any...

Hi All, I have created an elliptical region of interest in an image. Placed a bounding box, and worked out which pixels in the bounding box are within the elliptical ROI. Now I want to apply a 2D gaussian windowing technique to the region, such that it matches the elliptical shape. Can anybody tell me how I would go about doing that? Adam ...

Hello, does anybody know of a Mathematica program which converts an elliptic integral of the form int z^n/sqrt(P(z)) dz, where P is a fourth-order polynomial, into one of the standard forms? The reason that I would like this is to try and evaluate Integrate[ Exp[q*I*x]/(Sqrt(-A*Exp[4*I*x] - I*B*Exp[3*I*x] + (C+I*D)*Exp[2*I*x] + I*B*Exp[I*x] - A)), {x, 0, 2*Pi}, Assumptions -> {Element[q, Integers], A > 0, B > 0, C > 0, D > 0] but Mathematica won't do it in one go, even if I choose specific values for A, B, C, D and q. I believe that an analytic solutio...

Hi all, I'd like to limit the mouse cursor to a certain area of the screen. The reason is that I'm using a minimal window manager (ratpoison), but I still use the mouse a lot. Now menu bars often have a non-clickable border of 1 or 2 pixels. This makes it impossible to just slam the mouse upwards and click. For more about this problem, google for "mile high menu bar" or read this Joel on Software article (which is interesting even if you're not interested in my particular problem): http://www.joelonsoftware.com/uibook/chapters/fog0000000063.html In short...

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Art Geeks and Tech Geeks Come Together at New Workspace ,----[ Quote ] | Open Source is the name for what used to be called the Free | Software Movement. Their motto was free as in "freedom", not free | as in "beer". It was a revolution in grassroots | collaboration, and together, as a global team, sharing what they | knew and building upon the work of their fellows, they created a | computer operating system called Linux. The idea of the GNU | license is that you can have it for free, use it, build on it, | and even sel...

Hello, I'm having my first liaison with elleptic integrals - I'm trying to integrand:=1/(t^4+1)^(1/2)*t^2-1; int(integrand,t=-infinity..infinity); Well, this function is horrible - no residuals, nothing I learned (better: remember) how to calculate such beasts works. Maple gives me as a solution a combination of two elliptic integrals with complex arguments - but it's unable to calculate the limit t\to\infty, only evalf(int(integrand,t=-infinity..infinity)); Michael Michael Zedler wrote: > Hello, > > I'm having my first liaison with elleptic i...

Does anybody know the algorithm to draw elliptic arc. I know rx, ry, x axis rotation, end point Jan Krehlik wrote: > Does anybody know the algorithm to draw elliptic arc. I know rx, ry, x > axis rotation, end point Take a look at GEllipse2D class in the Amanith library. The algorithm to evaluate such an ellipse is linear and incremental (using gradient). Turbo - www.amanith.org ...

And here they are folks. The leaders of the Linux community in action. Show him the source? Somebody should show him the SHOWER !!!! http://www.abiword.org/~abi/expo99/expo_02_010_full.jpg Linux leaders panhandling on a NYC street corner. http://www.flickr.com/photos/fcb/68910570/in/set-1485493/ http://www.flickr.com/photos/fcb/68910250/in/set-1485493/ You can't make this stuff up.............. More about the Linux community can be found here: http://www.adequacy.org/stories/2001.11.26.101258.24.html (Check out the cartoons on the right side of the page) -- Moshe Goldfarb Col...

By RON FOURNIER, AP Political Writer Frustrated by government and empowered by technology, Americans are filling needs and fighting causes through grass-roots organizations they built themselves -- some sophisticated, others quaintly ad hoc. This is the era of people-driven politics. And politicians are understandably furious in many cases. From a homemaker-turned-kingmaker in Pittsburgh to dog owners in New York to a "gym rat" here in southwest Florida, people are using the Internet to do what politicians can't -- or won't -- do. This is their story, but it&#...

Hello, I would like to create an elliptical ROI on an image (I'm using a GUI - so this is user selected) that performs a calculation on the pixels in the image within the elliptical ROI. I would also like to be able to move the ellipsoid around once it has been created. Is there a way to do this in Matlab? Thanks so much for your help! maybe u could use rect = getrect; to select a rectangle and then use rectangle('position',rect,'Curvature',[1,1]) to create an ellipse (check help rectangle) another option is to use roipoly hope this helps, eitan JMM wrote: > >...

http://www.iop.org/EJ/article/1367-2630/6/1/162/njp4_1_162.html#nj186381s3 "Rayleigh's explanation [1, 2] of the polarization of clear-sky daylight, in terms of dipole radiation singly scattered by air molecules, would predict that light is unpolarized in the direction of the Sun or anti- Sun (anti-solar point), whichever is above the horizon. But observations had already demonstrated the existence of three unpolarized directions: above the Sun (the Babinet point), below the Sun (the Brewster point [3]) and above the anti-Sun (the Arago point), and hinted at a fourth point below the ...

Hello, I am trying to solve the equation int(1/sqrt(sinx))dx=Ct for x where C is constant and t is variable. when i integrate just the first part it gives result in terms of elliptical function and I could not understand how to use that. However I am pretty sure that the result of the integration part should be linear. Thank you in advance. Binu ...

Hi there, I'm currently writing a MDI application using 3 different childforms. For my application I need to know whether one of the childforms has been moved around, but I can't find the proper event for this...if there is any event for this at all. Can someone help me out here ? thx ...

Hi, I have a question about Elliptic PDEs in Matlab. As far as I know the most general form of Elliptic PDEs that Matlab can support is -div(c*grad(u))+a*u=f which is a little bit surprising since this general form can't support many other elliptic PDEs that don't fit in this form; (the general case is very limited)! e.g c*div(grad(u))-grad(c).grad(u)=f where "*" and "." represent the scalar and the dot product. Does anyone have a suggestion or the same experience on how to make those other Elliptic forms acceptable for Matlab? Or perhaps are you aware of other c...

I am a beginning user of the SimMechanics package. I am trying to build a model for a simple 1 dimensional automobile suspension. Essentially it is just 2 masses connected by a spring and damper. Currently my simple model looks something like: Ground->Prismatic->Mass 1->Prismatic(conncted to a joint spring and damper block-> Mass 2 Any time that I run the model with gravity activated in the machine environment block, the whole thing literally, "drops like a rock". I would like for there to be some way to restrict the prismatic joints to only allow a positive distance be...

Hi, I'm new to DSP and matlab and need some assistance.I’ve a waveform (sine like shape) in matlab which I want to apply in matlab a band-pass filter centered at 500kHz to it and then plot the response. I was wondering if someone can help me with the syntax to achieve this functionality? Thanks a million Regards, John On Aug 7, 7:07 am, "john1985" <murray_1...@hotmail.com> wrote: > Hi, > I'm new to DSP and matlab and need some assistance.I=92ve a waveform (sin= e > like shape) in matlab which I want to apply in matlab a band-pass filter > centered at 500k...

I realize EllipticModulus(x) is not defined if |x|=1. However, > EllipticModulus(1/sqrt(2)+I/sqrt(2)); starts calculating for a long period of time. I've never seen the end of this calculation(if it does end). Shouldn't it return an error? Is there a way to make it so that the EllipticModulus function checks the argument? --Jacques "Jacques" <jacqueslen@sympatico.ca> wrote in message news:a6439bfc.0401271309.3e10e4e8@posting.google.com... > I realize EllipticModulus(x) is not defined if |x|=1. However, > > > EllipticModulus(1/sqrt(2)+I/sqr...

Matlab function ellipke(m) is limited to the input domain 0<m<1. I have to compute complete elliptic integrals with a negative argument. Help! Thanks. ...

Hello, I am working on some elliptic curve (EC) cryptography stuff for a presentation. I have a routine that selects the the quadratic residues of an EC and than I pass that to a routine that finds the modular square roots of those QR points. Here are those two routines. *** selectQRList[a_, b_, p_] := Select[Range[p] - 1, JacobiSymbol[#^3 + a # + b, p] != -1 &]; ECPointList[a_, b_, p_, S_List] := Flatten[MapThread[Outer[List, #1, #2] &, {Partition[S, 1], SqrtModList[#^3 +a # + b, p] & /@ S}], 2]; *** Next, I want to draw the EC over the "reals&qu...

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Local council? Want to publish your data? Here’s how ,----[ Quote ] | In a very timely fashion, data.gov.uk has | come up with a blogpost explaining for any | local authorities who want to know (and | are listening/reading) how to publish | itemised local authority expenditure. `---- http://www.freeourdata.org.uk/blog/2010/06/local-council-want-to-publish-your-data-heres-how/ Opening up government finances ,----[ Quote ] | The following guest post is from Chris | Taggart of OpenlyLocal, who advises the | Where Does My...

Needs["Graphics`ImplicitPlot`"] ImplicitPlot[y^2 == x^3 + x + 1, {x, -2, 8}, {y, -10, 10}, PlotPoints -> 40]; Or we can make a parametric plot if we get the minimum value for x. xmin = x /. First@Solve[x^3 + x + 1 == 0] -(2/(3*(-9 + Sqrt[93])))^(1/3) + ((1/2)*(-9 + Sqrt[93]))^(1/3)/3^(2/3) ParametricPlot[ {{x, Sqrt[x^3 + x + 1]}, {x, -Sqrt[x^3 + x + 1]}}, {x, xmin, 6}, Frame -> True, Axes -> False] David Park djmp@earthlink.net http://home.earthlink.net/~djmp/ From: Berlid [mailto:jean_lee1998id@hotmail.com] Hello, everyone. Here, ...

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 EU Commission Approves Oracle-Sun Deal With No Conditions ,----[ Quote ] | I'm very grateful, personally, that the EU | Commission cares about Open Source, but after | its extensive investigation into MySQL, | despite some misinformation, as I viewed it, | it found, "The Commission's in-depth | investigation showed that although MySQL and | Oracle compete in certain parts of the | database market, they are not close | competitors in others, such as the high-end | segment." That is true. `---- http://...

Hi Does anyone have/know of a python implementation of the elliptic curve factoring algorithm (lenstra) which is both: simply and cleanly coded functional I'm aware of William Stein's code (from elementary number theory book) but I don't understand his coding style and the algorithm doesn't seem to work efficiently. For that matter has anyone come across any useable math/number theory packages apart from nzmath or aladim? Thanks Phil "Philip Smith" <as006d4848@blueyonder.co.uk> writes: > Does anyone have/know of a python implementation of the el...