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Re: AW: [Emc-developers] Re : Segmentqueue
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From: <eb...@sa...> - 2005-06-23 12:40:56
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8-) Well then, I wish you well on your academic journey of becoming, and too on your researches. Best regards, EBo -- Till Franitza <Till.Franitza@ISW.Uni-Stuttgart.de> said: > Dear EBo > i hope to become a "Doktor Franitza" some day, but until now i am obliged to > hint to the fact that i am not allowed to call myself Dr. . I am also not a > professor. I am only working as a researcher at the university. > Best regards, > Till > > > -----Ursprüngliche Nachricht----- > > Von: emc...@li... > > [mailto:emc...@li...]Im Auftrag von > > eb...@sa... > > Gesendet: Mittwoch, 22. Juni 2005 18:58 > > An: emc...@li...; Till Franitza > > Betreff: Re: [Emc-developers] Re : Segmentqueue > > > > > > > > Dr. Franitza> I understand. It would actually be a frightening > > amount of > > work for someone not already deeply read in math and GAGD. > > > > Ray> Thanks for that reference Ebo > > > > You are welcome. I also just noticed that Farin and Hansford > > just published > > a new book "Practical Linear Algebra: A Geometry Toolbox". That > > may also be > > of interest... > > > > Best regards, > > > > EBo -- > > > > Till Franitza <Till.Franitza@ISW.Uni-Stuttgart.de> said: > > > > > Dear EBo, > > > Bai is doing this as his Diploma Thesis, but you must consider > > that he is > > > not (yet) a very experienced programmer. I think your Hint sounds very > > > interesting, but I do not want to bother Bai with an upgrade of > > his task. > > > I will try to get the book in our library or buy it if possible. > > > Best regards, > > > Till > > > > > > > -----Ursprüngliche Nachricht----- > > > > Von: emc...@li... > > > > [mailto:emc...@li...]Im Auftrag von > > > > eb...@sa... > > > > Gesendet: Mittwoch, 22. Juni 2005 16:05 > > > > An: emc...@li...; Till Franitza > > > > Betreff: Re: AW: [Emc-developers] Re : Segmentqueue > > > > > > > > > > > > > > > > Depending on how far Bai and yourself wish to go into this, you > > > > may want to > > > > take a look at G. Farin's book "Curves and Surfaces for CAGD" > > > > (CAGD is short > > > > for Computer Aided Geometric Design -- the underlying geometric > > > > implementations/solutions used in CAD, GIS, etc.) If you get > > the 5'th > > > > edition there is some new material concerning Blossoms (based on > > > > Bernstein > > > > polynomial basis functions, if I recall correctly), which is a > > > > more efficient > > > > representation that have mathematically proven transformation > > to other > > > > surface representations. There are also some details in the book > > > > which cover > > > > how spirals can be created by transformations to the control knot > > > > sequence. > > > > Add to that Pathagorus-Hodigraph(not sure of the spelling) Curves > > > > (paramiterized in terms of arc-length, and you get constant velocity > > > > basically for free). This is the direction I would go if I ever > > > > decide to > > > > pick the subject back up again. > > > > > > > > I should ask at this point if this is Bai's undergraduate > > honors thesis, > > > > masters thesis, or part of a PhD dissertation? Here in the US, > > > > Farin's book > > > > is typically presented to masters or PhD candidates. One of the > > > > exercises > > > > Farin gave in his book can be used to generate motion profiles > > > > for a 6-DOF > > > > machine. You might also want to take a look at Farin&Hansford's "The > > > > Essentials of CAGD" which is the book Farin uses for his > > undergraduate > > > > classes. > > > > > > > > I hope this is useful... > > > > > > > > > > > > EBo -- > > > > > > > > > Hallo Paul, > > > > > Bai is implementing the 7 phases as a thesis work here. > > > > > What do you mean by the wasteful memory allocation? Is that a > > > > problem when > > > > > we use some megabytes? I wouldnt mind. We have plenty of it. > > > > Ram is cheap. > > > > > With the floating point operations... i am not sure but i got the > > > > impression > > > > > that the calculations in segmantqueue are quite efficient. > > The use of > > > > > posemath makes more sense than doing everything with own > > > > functions. My idea > > > > > was to give the student a task where he has a basis to start > > > > from. So i > > > > > thought segmentqueue is ideal. I think there is a lot to learn > > > > just from > > > > > studying the segmentqueue code. > > > > > Why don't spirals work? Is there something missing that i > > could add? > > > > > Regards, > > > > > Till > > > > > > > > > > > -----Ursprungliche Nachricht----- > > > > > > Von: emc...@li... > > > > > > [mailto:emc...@li...]Im Auftrag > > > > von Paul > > > > > > Gesendet: Montag, 20. Juni 2005 17:09 > > > > > > An: emc...@li... > > > > > > Betreff: Re: [Emc-developers] Re : Segmentqueue > > > > > > > > > > > > > > > > > > > > > > > > Hi Bai > > > > > > > > > > > > On Monday 20 June 2005 15:50, Xiaoning Bai wrote: > > > > > > > now I beginn to upgrade this segmentqueue, there will > > > > > > > be 7 phases instead of 3 phases and I will start to > > > > > > > calculate the phase periods (T1 ... T7)instead of > > > > > > > steps (sq->m, sq->p and sq->q). I hope a jerk-limited > > > > > > > segmentqueue ( with trapezoidal acc/dec profile) will > > > > > > > be soon realized. > > > > > > > > > > > > With the heavy use of posemath, along with all the convoluted > > > > > > algorithms used, > > > > > > would it not be easier to start with a clean sheet ? > > > > > > Extending segmentqueue to accept NURBS or Bezier splines would be > > > > > > an ardous > > > > > > task, and extending it to cope with seven or even eight axis is > > > > > > impossible. > > > > > > Nor would I even want to contemplate adding threading support to > > > > > > the code.. > > > > > > > > > > > > I can't help but wonder if the huge amount of floating point > > > > > > calculations is > > > > > > really an efficient use of resources. Certainly the > > amount of memory > > > > > > allocated for the queue is wastefull. > > > > > > > > > > > > > > > > > > Regards, Paul. > > > > > > > > > > > > > > > > > > -- > > > > > > Pieces of seven, pieces of seven - A parroty error. > > > > > > "To err is human...to really f*** things up requires the root > > > > password." > > > > > > From a collection of quotes at http://www.indigo.org/quotes.html > > > > > > > > > > > > > > > > > > ------------------------------------------------------- > > > > > > SF.Net email is sponsored by: Discover Easy Linux Migration > > > > Strategies > > > > > > from IBM. Find simple to follow Roadmaps, straightforward > > articles, > > > > > > informative Webcasts and more! Get everything you need to > > get up to > > > > > > speed, fast. http://ads.osdn.com/?ad_idt77&alloc_id492&op=ick > > > > > > _______________________________________________ > > > > > > Emc-developers mailing list > > > > > > Emc...@li... > > > > > > https://lists.sourceforge.net/lists/listinfo/emc-developers > > > > > > > > > > > > > > > > > > > > > > > > > > ------------------------------------------------------- > > > > > SF.Net email is sponsored by: Discover Easy Linux Migration > > Strategies > > > > > from IBM. Find simple to follow Roadmaps, straightforward articles, > > > > > informative Webcasts and more! Get everything you need to get up to > > > > > speed, fast. > http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click > > > > _______________________________________________ > > > > Emc-developers mailing list > > > > Emc...@li... > > > > https://lists.sourceforge.net/lists/listinfo/emc-developers > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > > > > > > > > > > > ------------------------------------------------------- > > > SF.Net email is sponsored by: Discover Easy Linux Migration Strategies > > > from IBM. Find simple to follow Roadmaps, straightforward articles, > > > informative Webcasts and more! Get everything you need to get up to > > > speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click > > > _______________________________________________ > > > Emc-developers mailing list > > > Emc...@li... > > > https://lists.sourceforge.net/lists/listinfo/emc-developers > > > > > > > > > > > ------------------------------------------------------- > > SF.Net email is sponsored by: Discover Easy Linux Migration Strategies > > from IBM. Find simple to follow Roadmaps, straightforward articles, > > informative Webcasts and more! Get everything you need to get up to > > speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click > > _______________________________________________ > > Emc-developers mailing list > > Emc...@li... > > https://lists.sourceforge.net/lists/listinfo/emc-developers > > > > > > > > -- > > > > > ------------------------------------------------------- > SF.Net email is sponsored by: Discover Easy Linux Migration Strategies > from IBM. Find simple to follow Roadmaps, straightforward articles, > informative Webcasts and more! Get everything you need to get up to > speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click > _______________________________________________ > Emc-developers mailing list > Emc...@li... > https://lists.sourceforge.net/lists/listinfo/emc-developers > > > > ------------------------------------------------------- > SF.Net email is sponsored by: Discover Easy Linux Migration Strategies > from IBM. Find simple to follow Roadmaps, straightforward articles, > informative Webcasts and more! Get everything you need to get up to > speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click > _______________________________________________ > Emc-developers mailing list > Emc...@li... > https://lists.sourceforge.net/lists/listinfo/emc-developers > > -- |