Author Topic: Question about one error message./board:23-101-  (Read 32094 times)

ahmedelshfie

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Re: Question about one error message./board:23-101-
« Reply #15 on: July 20, 2011, 12:01:16 am »
May you attach images for what you want , for me can have idea, i can also modified applet for be like you want, but as i said will be helpful
that you attach some images show the object that you want, this help professor Hwang, lookang and me to help you.

For example here is a simple modified i done, the original applet created by prof Hwang.

Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
  • Please feel free to post your ideas about how to use the simulation for better teaching and learning.
  • Post questions to be asked to help students to think, to explore.
  • Upload worksheets as attached files to share with more users.
Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!
« Last Edit: July 20, 2011, 01:36:50 am by ahmedelshfie »

lookang

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Re: Question about one error message./board:23-101-
« Reply #16 on: July 20, 2011, 09:18:48 am »
the applet above looks modified by ahmed! nice one :)
where is the link for the applet? it is on your board? i cannot find it
« Last Edit: July 20, 2011, 09:21:00 am by lookang »

Fu-Kwun Hwang

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RE: EJS Examples: how to import an image and let the image rotate!
« Reply #17 on: July 20, 2011, 12:20:57 pm »
You are welcomed to check out the following simple examples:


ahmedelshfie

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Re: Question about one error message./board:23-101-
« Reply #18 on: July 20, 2011, 06:05:50 pm »
Thanks, yes in my board you can find at http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1723.0

For Alex_10, i hope this what you need, for you watch the applet you need to click on the eye image.

Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
  • Please feel free to post your ideas about how to use the simulation for better teaching and learning.
  • Post questions to be asked to help students to think, to explore.
  • Upload worksheets as attached files to share with more users.
Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!

 
« Last Edit: July 20, 2011, 08:07:51 pm by ahmedelshfie »

Alex_10

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Re: Question about one error message./board:23-101-
« Reply #19 on: July 20, 2011, 11:40:00 pm »
Thank you for all the things that you are sending me  ;)

I don't know miss something in my exercise but i thing i'm really close, know the satellite turn, but in one moment disappear.

I attach all the things that i have, all the information about the exercise, like this may be your answer are completily usefull for me.

1º I attach the picture of the thing that should turn, this object should have one move of rotation. Have two views but the simulation shuold be in 2D.

2º I attach the ecuations with that should have this object (satellite).

3º I attach my .xml

4º  Is a control system the angle "?" of an axis of a satellite using a rotating wheel. To vary the angular velocity of the satellite "?" changes the angular velocity of the wheel "v" by a motor located in the satellite.

Data:
  (? = v - ?) both are angular velocity.
  B = 1,01.10-6 (N.ms/rad) viscous friction coefficient.
  J1 = 13,6 kg.m2 moment of inertia of the satellite
  J2 = 13,6.10-4 kg.m2 moment of inertia of the flywheel.
  Je equivalent moment of inertia.
  T torque developed by the motor.

 

ahmedelshfie

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Re: Question about one error message./board:23-101-
« Reply #20 on: July 21, 2011, 12:09:22 am »
Well, your XML code doesn't work with me, is frozen, i try find the reason to this error, however try look for the last applet and how rotate is work
look to variables pi,c and also look to Evolution page last variable is dc.







ahmedelshfie

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Re: Question about one error message./board:23-101-
« Reply #21 on: July 22, 2011, 09:05:16 pm »
You should to check the variable o initial value =20 , i believe this variable is the reason to object disappear when you run the applet, try check.

For example try delete o form first shape (open Satelite, down at transform you add variable o delete) and run the applet again.
« Last Edit: July 22, 2011, 09:31:18 pm by ahmedelshfie »

Alex_10

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Re: Question about one error message./board:23-101-
« Reply #22 on: July 22, 2011, 11:56:40 pm »
I tried this before and doesn't work. I change all the variables, and the initial values....  ???

ahmedelshfie

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Re: Question about one error message./board:23-101-
« Reply #23 on: July 23, 2011, 12:09:30 am »
Well, as i said in my last post to you watch object you have to delete o variable i already test this and later i run applet the object is appear. I'm gonna attach image please
Check image i attach down post.
You should to delete this variable and run applet again object will appear try it.

Alex_10

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Re: Question about one error message./board:23-101-
« Reply #24 on: July 23, 2011, 07:54:04 pm »
Yes this is true, but if you put out this variable the object doesn't move, is totally stop.

Fu-Kwun Hwang

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Re: Question about one error message./board:23-101-
« Reply #25 on: July 23, 2011, 10:45:09 pm »
Normally, transform is used to rotate the object or change it width or height (shape) ...etc.

If you want to move an object, you can define variable x,y and assign them to Pos X and Pos Y.
Then provide equation to specify how x,y should change with time.

e.g. if you define dx/dt=vx; then the object will move with velocity vx in x direction.

Alex_10

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Re: Question about one error message./board:23-101-
« Reply #26 on: July 24, 2011, 12:25:18 am »
I tried to do this also, but the problem is that i put the refence in the middle of the object, so in my case PosX = 0 and PosY = 0 all the time.

If i separate the componet x and the componet y, i would have to put the reference in a corner of the object. And i was searching this option for change the reference and i didn't find it.  ???

Fu-Kwun Hwang

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Re: Question about one error message./board:23-101-
« Reply #27 on: July 24, 2011, 10:59:37 am »
Pos X and Pos Y are (x,y) coordinate for center of the object.

The default for (x,y) is refer to middle of the object. (You can change Offset property to change it;s reference point).

You should define x,y and set Pos X, Pos Y properties to x and y.

You are welcomed to check out description for those properties at http://www.um.es/fem/EjsWiki/Main/ElementsShape2D