Re: [Visualpython-users] Getting a simple graph animation plot to show

[Lenore H. <lh...@si...>]

On Jan 9, 2010, at 07:41 , John Brennan wrote:

> I having difficulty in trying to display two windows one with action/ 
> animation and the graph that relates to the action. I tried to put  
> together pieces from the documentation on graphs. I want to graph  
> the time by speed of the accelerated ball in the animated window.  
> The code below does succeed in running the animation and can display  
> the graph window but I cannot get the plotting function to display  
> on the graphing window I created. Does the curve need to be an  
> argument with gdisplay at the beginning but that isn't a clear  
> parameter in the documentation. Within the motion loop, I feel like  
> there should be something like graph1 = gdisplay(funct1) to relate  
> the function to the graph window but it isn't clear how to do this.  
> What is the best and tidiest way to do this?
>
> # Adapted from erik thompson video lesson 1.
>
> from visual import *
> from visual.text import *
> from visual.graph import * # import graphing features
>
> scene.width = 800
> scene.height = 600
>
> scene.autoscale = 0
> scene.range = (100,100,100)
> scene.center = (0,40,0)
>
> scene.title = "Acceleration"
> scene.fov = 0.001
> #scene.range = 7                 #sets the starting position view.
>
> ball = sphere(pos=(100.0,0,0),radius=2)
> ground = box(pos=(-1,0,0),size=(2,10,10))
>
> initPos = ball.pos
> acc = 9.8   # m/s**2
> seconds = 0.0
> dt = .01    #change in time
>
> graph1 = gdisplay(x=0, y=600, width=600, height=500,
>         title='dt vs. dv', xtitle='change in time', ytitle='change  
> in speed',
>         xmax=30, xmin=0., ymax=25, ymin=0,
>         foreground=color.black,  
> background=color.white)                    # is gcurve an argument  
> that should go in here
>
> graph1 = gdisplay()
> graph1.display.visible = 0 # make the display visible
>
> finished = False
> while not finished:
>
>     rate(100)   # sets the general rate and speed of the computations
>     seconds += dt    #increment time
>
>
>     distance = 0 + .5 * acc * seconds**2 #distance travelled
>     time = seconds
>     speed = distance / time
>
>     funct1 = gcurve(color=color.cyan)
>     graph1 = gdisplay(funct1)           #I know this is wrong but  
> how do I place on graph1.
>     for time in arange(0.0, 30.0, 0.1):    # time is a range that  
> goes from 0 to 30 (in increments of 0.1).
>         funct1.plot(pos=(time,speed))    # plot a time by speed graph.
>
>     # position equation: y(t) = y0 + v0*t + .5 * a * t**2. So the  
> position of the ball at any given instance is...
>     ballTravel = 100.0 - .5 * acc * seconds**2
>
>     #new position
>     ball.pos = vector(ballTravel,0,0)
>
>     if ballTravel - 2 < 0:       #try to stop at 1 on the platform
>         finished = True
>         print "seconds to fall: " + str(seconds)        #print to  
> the display console.
>
Here are relevant snippets from my code.

Xvel = gdisplay(x=0,y=0, width=262, height=100,  
background=color.white, xmin=0, xmax=12, ymin=-vmax, ymax=vmax, title  
= 'V_x(t)')
Xvelnodrag = gdots(size=3, color=nodragcolor)

  Xvelnodrag.plot( gdisplay=Xvel.display, pos=(t,nodrag.velocity.x) )


Lenore