Ok, that is clearer. So your reference frame has a notion of time whereas, Prasoon's base classes only have notion of space. Correct?
Jason moorepants.info +01 530-601-9791 On Thu, Mar 13, 2014 at 1:56 PM, Sachin Joglekar <[email protected]>wrote: > I agree. Hence, the classes I plan to build on top of Prasoon's core will > have time-dependent functionality to support motion. > > > On Thu, Mar 13, 2014 at 11:23 PM, Tim Lahey <[email protected]> wrote: > >> I think it's necessary to have a reference frame that changes with >> respect to time. Even something such as simple link can have a frame that >> rotates with respect to the inertial frame. A rotating frame makes dealing >> with the equations for a flexible link simpler. Plus, it's useful for >> multi-body systems as well. >> >> Cheers, >> >> Tim. >> >> >> On 13 Mar 2014, at 13:29, Sachin Joglekar wrote: >> >> Okay my words may have been a little confusing. To explain the terms >>> better- >>> *rotated* - oriented at a certain angle wrt the parent system >>> *translated* - the origin of the translated system has a non-zero >>> position >>> >>> vector wrt the parent system >>> >>> To put it more clearly, the orientation of the child system and the its >>> origin's position vector are _not_ functions of time. Essentially, >>> Prasoon's code does not deal with time at all. Its good to do simple >>> vector >>> calculus that does not involve time as a factor. >>> By motion, I meant a system whose orientation/translation wrt its parent >>> change with time. >>> >>> >>> On Thu, Mar 13, 2014 at 10:50 PM, Jason Moore <[email protected]> >>> wrote: >>> >>> "A coordinate system is a mathematical concept that helps one describe >>>> points or vectors(directions) in space. A reference frame, on the other >>>> hand, is the extension of this concept to involve motion (time-dependent >>>> quantities). Coordinate Systems may be rotated/translated with respect >>>> to >>>> each other, *but* they are stationary." >>>> >>>> >>>> I don't understand this. How can a coordinate system be rotated and >>>> translated yet be stationary. What is your definition of "motion"? >>>> >>>> >>>> Jason >>>> moorepants.info >>>> +01 530-601-9791 >>>> >>>> >>>> On Thu, Mar 13, 2014 at 12:31 PM, Sachin Joglekar < >>>> [email protected] >>>> >>>>> wrote: >>>>> >>>> >>>> Hello everyone. >>>>> >>>>> I have put up my proposal for the SymPy/PyDy project on creating a >>>>> general-purpose vector calculus module for sympy. It will be a >>>>> continuation >>>>> of the work that was done by Prasoon and I last summer, and hopefully I >>>>> plan to conclude it this time (much of it is currently unmerged). The >>>>> details of the project are in my proposal at this link< >>>>> https://github.com/pydy/pydy/wiki/GSoC-2014- >>>>> Application:-srjoglekar246:-sympy.vector-module> >>>>> >>>>> . >>>>> @Ondrej, Aaron, Stefan - please give your inputs for the same. >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups >>>>> "sympy" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an >>>>> email to [email protected]. >>>>> To post to this group, send email to [email protected]. >>>>> Visit this group at http://groups.google.com/group/sympy. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/sympy/28a5bbe3-d6d7- >>>>> 40a7-ae9e-6665524bf116%40googlegroups.com<https:// >>>>> groups.google.com/d/msgid/sympy/28a5bbe3-d6d7-40a7-ae9e- >>>>> 6665524bf116%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> >>>>> . >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>>> >>>> -- >>>> You received this message because you are subscribed to a topic in the >>>> Google Groups "sympy" group. >>>> To unsubscribe from this topic, visit >>>> https://groups.google.com/d/topic/sympy/ux3MVAc9jeQ/unsubscribe. >>>> To unsubscribe from this group and all its topics, send an email to >>>> [email protected]. >>>> To post to this group, send email to [email protected]. >>>> Visit this group at http://groups.google.com/group/sympy. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/sympy/CAP7f1Aj2UhWxRyD3bumZ-DnhHNgJ% >>>> 3DZ6OJQVhWa9%3Dn3SQVhbDOg%40mail.gmail.com<https:// >>>> groups.google.com/d/msgid/sympy/CAP7f1Aj2UhWxRyD3bumZ- >>>> DnhHNgJ%3DZ6OJQVhWa9%3Dn3SQVhbDOg%40mail.gmail.com? >>>> utm_medium=email&utm_source=footer> >>>> >>>> . >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "sympy" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To post to this group, send email to [email protected]. >>> Visit this group at http://groups.google.com/group/sympy. >>> To view this discussion on the web visit https://groups.google.com/d/ >>> msgid/sympy/CALMMyxZY5ev5-b1gVMGc%3DYroHtw3QHb34W0fFZ3kt7pEdShNY >>> g%40mail.gmail.com. >>> >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- >> You received this message because you are subscribed to a topic in the >> Google Groups "sympy" group. >> To unsubscribe from this topic, visit https://groups.google.com/d/ >> topic/sympy/ux3MVAc9jeQ/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/sympy. >> To view this discussion on the web visit https://groups.google.com/d/ >> msgid/sympy/D52476D7-6B0D-4EFB-98C8-0A1AD20D9F8E%40gmail.com. >> >> For more options, visit https://groups.google.com/d/optout. >> > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/sympy. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/CALMMyxb7GnofawspJYBOL2y8%2Byha3YKt9SCoVYKH3dkyi6cQ8Q%40mail.gmail.com<https://groups.google.com/d/msgid/sympy/CALMMyxb7GnofawspJYBOL2y8%2Byha3YKt9SCoVYKH3dkyi6cQ8Q%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "sympy" group. 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