EJS version of Fourier Synthesis (You can hear the sound,too!)

[Fu-Kwun Hwang]

I have created a Fourier Synthesis in 1999.
Here is the EJS version of Fourier Synthesis.

You can adjust the Fourier component with the slider and watch the wave change at the same time.
Click "play" to hear the sound.

Click get button to fetch coefficients. Click set button to modify coefficients.
Please click get button first,before you click set button.

	0f	f	2f	3f	4f	5f	6f	7f	8f	9f
sin
cos

Embed a running copy of this simulation
<applet code='users.ntnu.fkh.fouriersound_pkg.fouriersoundApplet.class' archive='http://www.phy.ntnu.edu.tw/ntnujava/ejsuser/2/ejs_fouriersound.jar' name='fouriersound4021' id='fouriersound4021' width='847' height='541' 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=4021' 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!

[Fu-Kwun Hwang]

I add a musical keyboard just for fun. ENjoy it!

Embed a running copy of this simulation
<applet code='users.ntnu.fkh.musicalkeyboard_pkg.musicalkeyboardApplet.class' archive='http://www.phy.ntnu.edu.tw/ntnujava/ejsuser/2/ejs_musicalkeyboard.jar' name='musicalkeyboard4373' id='musicalkeyboard4373' width='796' height='144' 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=4373' 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]

The EJS version of Fourier Synthesis is wonderful. It is truly remarkable.

By the way on the topic of importing external jar,
Variable declaration The type is fkh.SoundGenerator
so i think it is because of the imported jar file name ./jar/fkh.SoundGenerator.jar


The code assigned variable "sound" to new initial value of fkh.SoundGenerator(frequence,amplitude)..... how do i know it is (frequence,amplitude) and not (frequence,amplitude, XYZ,ABC)?
Does it mean i also need to look inside (the eariler *.java etc??) "fkh.SoundGenerator.jar" before i know how to use it?

The reason i am asking is i don't know how to use my own imported filter.jar here http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1400.msg5271#msg5271
i am clueless

[Fu-Kwun Hwang]

1.The jar file is the same as ZIP file. The only difference is the file extension.
So you can open it with UNZIP program. (Do not associate jar with UNZIP program, otherwise, you would not be able to run it by double click--UNZIP will open it instead.).

2. You will find a folder fkh inside the jar file when you open my soundGenerator.jar
And there is a file soundGenerator.class inside fkh folder,
 and there is a function call SoundGenerator(frequence,amplitude) inside soundGenerator.class
That is why it is associated as fkh.soundGenerator function.

You will need to have source code or document in order to know what are the parameter for that function.

It is possible to de-compile the program if the program is not protected when it is compiled.
There exists some program to de-compile .class file back to .java
However, the best way is to find the original document or ask the programmer.

User need to find out how to use ConvolveFilter from the source code.
http://www.huxtable.com/ip/ConvolveFilter.java
You can call defined public functions with required parameters.

However, user need to have basic information about java programming.
That is why EJS is called Easy Java Simulation, becauase it make java programming much easier than traditional programming.

[lookang]

great applet.
What will make this applet even more useful is an microphone input.
students can speak into a microphone on their computer  and the PC display (java applet) shows the shape of the waveform.

maybe another applet?

[Fu-Kwun Hwang]

There is a free program can do this : audacity
Do we need to duplicate the work?

[lookang]

Agreed!
I will used audacity to explore voice generated waveforms.
Thanks for the tip!

[N Burling]

Love this site apps are get for assisting with teaching (high school).

Is it possible to get the files for the EJS version of the fourier synthesis.  I have some students struggling with timbre of musical instruments.

Thanks

[Fu-Kwun Hwang]

Yes. The simulation is available for offline use.
You should be able to find download button when you login to the forum.

[balijani]

great work! 

[sajidtoor]

Hi
welcome to all,i'm newly in this forum.
http://www.phy.ntnu.edu.tw

[sajidtoor]

Hi
welcome to all,i'm newly in this forum.