how do make Ejs applet run forever unless the pause or reset

[lookang]

how do make Ejs applet run forever (time increase by dt ) unless the pause or reset?

i have a strange applet which i remixed from, i tried to track down the codes for the end of simulation but i don't see any.

any idea what is causing the applet to end?

you can make the applet end by changing e=0, i thought it would continue to count t which is what i wanted.

Embed a running copy of this simulation
<applet code='users.sgeducation.lookang.Car2_pkg.Car2Applet.class' archive='http://www.phy.ntnu.edu.tw/ntnujava/ejsuser/14019/ejs_Car2.jar' name='Car26643' id='Car26643' width='600' height='600' mayscript=true><param name='draggable' value='true'></applet>
Embed a running copy link(show simulation in a popuped window)
<a href='http://www.phy.ntnu.edu.tw/ntnujava/msg.php?smfejs=6643' target='smfejs'>Run simulation</a>

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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

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[Fu-Kwun Hwang]

I did check out your ejs code.
There are several strange code
1. Why the drawingPanel was assigned to be autoscale?
2. Why maxX= -carSize/2
3. Why Lmax was not defined?
...

You should have assigned initlal value for defined variables.
I do not know how to change your code because I do not know the specification for your simulation.

The code in the event are strange,too!

If I have something bounced between xmin and xmax (xmax>xmin)

I will have code like this for zero condition:

Code:

if (v>0)return x-xmax; // bounced at x=xmax
else if(v<0)return x-xmin; // bounced at x=xmin
return 1;

// the event occurs when return value is less than zero.

And the action will be

Code:

v=-e*v;

Embed a running copy of this simulation
<applet code='users.ntnu.fkh.bump_pkg.bumpApplet.class' archive='http://www.phy.ntnu.edu.tw/ntnujava/ejsuser/2/ejs_bump.jar' name='bump6646' id='bump6646' width='472' height='526' mayscript=true><param name='draggable' value='true'></applet>
Embed a running copy link(show simulation in a popuped window)
<a href='http://www.phy.ntnu.edu.tw/ntnujava/msg.php?smfejs=6646' target='smfejs'>Run simulation</a>

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!

[lookang]

I did check out your ejs code.
There are several strange code
1. Why the drawingPanel was assigned to be autoscale?

so that maximum view is achieved.
Lmax was original 10, i need to customize it to only 1 metre cos in school, the length of the ramp is about 1.2 m
if i keep Lmax = 10 m, and i vary L, the mainview becomes a very small car and ramp with about of empty space, because L = 10m, so i made L = 1m
and with autoscale, the view is squared and maximum. should i make the view constant?

2. Why maxX= -carSize/2

it is commented cos i was debugging it.
Fixed relations.FixRel Page(43): //maxX= -carSize/2;

3. Why Lmax was not defined?

Lmax = 0.

You should have assigned initlal value for defined variables.

ok, but i blank them because the applet accepts new values after reset button, which is how i make the applet remember/stored previous user inputs without much troublesome variables assignment techniques such as variable_stored to remember last user values.

I do not know how to change your code because I do not know the specification for your simulation.

The code in the event are strange,too!

If I have something bounced between xmin and xmax (xmax>xmin)

I will have code like this for zero condition:

Code:

if (v>0)return x-xmax; // bounced at x=xmax
else if(v<0)return x-xmin; // bounced at x=xmin
return 1;

// the event occurs when return value is less than zero.

And the action will be

Code:

v=-e*v;

interesting, i never did zero crossing before! thx for the tip!

i modify the idea from Ejs default examples http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=797.0
but you are right, i could not get the applet to detect the state correctly sometimes, so i changes the dt =0.1 to 0.05 s thinking it will lesser the detection state error.
i have adopted your zero crossing method

Code:

if (v>0) return x+carSize/2-xbumperbottom; // bounced at x=xmax
else if(v<0)return x-carSize/2-xbumpertop; // bounced at x=xmin or x+carSize/2
return 1.0;
//return 1.0;

action

Code:

v=-e*v;

will try all the more elegant coding!
thx!

[Fu-Kwun Hwang]

ok, but i blank them because the applet accepts new values after reset button, which is how i make the applet remember/stored previous user inputs without much troublesome variables assignment techniques such as variable_stored to remember last user values.

The effect you need is better done with _initialize() instead of _reset()

Write code need to be initialized at initlalize page and EJS will remember user's inputs.

_reset() is used to restart everything.