Where communities thrive


  • Join over 1.5M+ people
  • Join over 100K+ communities
  • Free without limits
  • Create your own community
People
Repo info
Activity
    Angadh Nanjangud
    @angadhn
    yes.
    Jason K. Moore
    @moorepants
    they are both the same thing
    Angadh Nanjangud
    @angadhn
    no
    Jason K. Moore
    @moorepants
    you can still write v.tilde(w)
    Angadh Nanjangud
    @angadhn
    they are not
    Jason K. Moore
    @moorepants
    yes they are
    they both have th same info
    we choose to use the left side when designing mechanics
    we could have easily chosen the right side
    Angadh Nanjangud
    @angadhn
    the basis for the first 3 components and next 3 components are the same
    actually they are completely different!
    Jason K. Moore
    @moorepants
    the basis is defined in A
    they are the same!
    Angadh Nanjangud
    @angadhn
    no!
    V = [velocity, angular vleocity]
    V is spatial veclotiy
    V != v + w
    V_linVel = v
    V_angVel = angular velocity
    they are components of tow different vectors
    they do not live in R6
    but actually in R3cross3
    Jason K. Moore
    @moorepants
    you can write it like SpatialVector(v, w, A) if you want
    same thing
    Angadh Nanjangud
    @angadhn
    which is what I offer
    Jason K. Moore
    @moorepants
    gotta go bye
    Angadh Nanjangud
    @angadhn
    if you look at attributes, it V.w and V.v
    later!
    also from the book: "Strictly speaking spatial vectors live in the
    R3√óR3 space, but for notational simplicity we will treat them as members of the
    R6 space."
    my point is that spatial velocity is not a sum of angular and linear velocities
    yibochallinger
    @yibochallinger
    is there a good example using pydy.viz?
    yibochallinger
    @yibochallinger
    @moorepants where to find the code to Conical Pendulum Visualization with PyDy? did you generate javascript from python?
    Angadh Nanjangud
    @angadhn
    @yibochallinger https://github.com/pydy/pydy-tutorial-human-standing works pretty well to show you the ropes on using viz. notebook 8 is on viz.
    Jason K. Moore
    @moorepants
    @yibochallinger the examples are in the examples directory in the pydy repository
    yes we generate javascript
    extraymond
    @extraymond
    Sorry for asking a rather vague question:
    But anyone know any information about this document? https://www.scribd.com/document/280283656/Modeling-Squat-Jump
    It stated that it's using pydy, would like to know if there is any more of this.
    Jason K. Moore
    @moorepants
    @extraymond looks interesting, didn't know about it, seems you can't download it without an account on that website
    extraymond
    @extraymond
    @moorepants I've been looking for reference files or citing about this document, but nothing but the one on scribd.com can be found.
    yibochallinger
    @yibochallinger
    I followed pydy tutorial human standing example hoping to create a visualization for a quadcopter but pydy.viz doesn't display any objects.
    Renato Marinho
    @renatomarinho
    This message was deleted
    Renato Marinho
    @renatomarinho
    This message was deleted
    Sam Brockie
    @brocksam
    Hi. What's the simplest way to extract numerical values for Derivative(u, t) from a pydy System object following running System.integrate()? I know System.integrate() returns a np.ndarray with each column corresponding to the vector of q and u states for the system. But if one derives the EoM with auxiliary speeds to bring into evidence noncontributing forces then these can be functions of the time derivatives of the speeds. Or is there a more efficient way to numerically evaluate these noncontributing forces from the auxiliary equations? Many thanks, Sam
    Jason K. Moore
    @moorepants
    The system object currently does not track anything extra. You can lambdify the expressions you want to calculate and then provide the results from system.integrate() to the function generated from lambdify.
    extraymond
    @extraymond
    @yibochallinger If your using jupyter lab, I think the widget is coming out like what it does with jupyter notebook.
    Foad Sojoodi Farimani
    @fsfarimani_twitter
    Hey guys, I'm very new to PyDy. I was wondering if there are any examples for 1. 3D mechanisms 2. parallel / closed mechanisms? Thanks for your help in advance
    Foad Sojoodi Farimani
    @fsfarimani_twitter
    Hi everybody, I opened a new issue pydy/pydy#412 I would appreciate if you could help me find a solution. Thanks in advance.
    Foad Sojoodi Farimani
    @fsfarimani_twitter
    the link to "Inverted pendulum model of a standing human" on this page seems to be broken as I have reported pydy/pydy#413
    Foad Sojoodi Farimani
    @fsfarimani_twitter
    Hi guys, I would appreciate if you could help me with this question from Kane 1985 book.