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Thanks to Lalit
lotollotol 20 Sep 2017 17:21
in discussion Kojo / Kojo-Dev » geogebra with kojo

You need to reply for the previous post.

I am impressed by your project. I would wish Kojo to be used in every school.

Thanks to Lalit.

Thanks to Lalit by lotollotol, 20 Sep 2017 17:21
weonkyoung yu (guest) 20 Sep 2017 14:34
in discussion Kojo / Kojo-Dev » geogebra with kojo

Thank you for your prompt reply.

I have another question.

I am a math teacher in senior high school. In Kojo, Would it be possible to script number theory, mathematical modeling and so on?

by weonkyoung yu (guest), 20 Sep 2017 14:34

Yes, you can programatically control geogebra from Kojo via scala scripts. The bridge is the Mw object in Kojo.

For example, try this script:

Mw.variable("m", 1, -5, 5, 0.1, 50, 50)
Mw.variable("c", 0, -2, 2, 0.1, 50, 80)
Mw.evaluate("y = m x + c")

To see more examples, look (in the script editor) at the scripts for Help -> Kojo Overview and Samples -> Math Learning Modules -> Solving Linear Equations (run these scripts, and then search for Mw. in the script editor)

Code completion on the Mw object (type Mw. and then Ctrl+Space) will show you what's available for geogebra interaction.

Or you can look at the Mathworld class (of which the above Mw is an instance) to see what's inside in more detail:

Hope that helps. Feel free to ask more questions.

Re: geogebra with kojo by lalitplalitp, 20 Sep 2017 13:36
geogebra with kojo
weonkyoung Yu (guest) 20 Sep 2017 12:21
in discussion Kojo / Kojo-Dev » geogebra with kojo

In gegogebra, constructions and computations can be done using input filed command, ggbscript and javascript.
Can I do the same thing with kojo script

geogebra with kojo by weonkyoung Yu (guest), 20 Sep 2017 12:21

Yes you can, after liberating your student's machines: ChromeOS is actually prepared for running a Linux Ubuntu subsystem! Programming is all about controlling your computer so when teaching programming it makes perfect sense to unlock your Chromebook and use developer mode and then install what is called "Crouton" on your Chromebook.

Here is one of many guides on the net on how to do that:

The you install Java with this terminal command in your Ubuntu subsystem:

sudo apt-get install default-jdk

And then install Kojo as described for Linux on the Kojo download page. And ready to go!

BTW: This means that the sysadmin of your school should support your very important pedagogical ambitions in allowing your students to do "real" programing! :)

Hope this helped?

Good luck!

Kojo och chrombooks
Annamaria Kadir (guest) 24 Aug 2017 06:50
in discussion Kojo / Support » Kojo och chrombooks

Mina elever har chromebooks. Går det att jobba med Kojo?

Kojo och chrombooks by Annamaria Kadir (guest), 24 Aug 2017 06:50

The question in English: "Is it possible to run Kojo on a Chromebook with ChromeOS, and if so how to do it?"

Yes, it is possible but requires that you enable developer mode, and you then can install crouton via commands in a terminal window as explained here:

After that you can install openjdk using this command in terminal:

sudo apt-get install openjdk-8-jre

and then download and run the kojo jar-file from terminal using this command:

java -jar xxx.jar

where xxx.jar is replaced by the name of the downloaded kojo jar-file from here:

If you have problems, your IT-department should be able to help you with the installation.
Good luck!

Kojo på en chromebook
Ann-Catherine Sjöberg (guest) 12 May 2017 06:55
in discussion Kojo / Kojo-User-Sweden » Kojo på en chromebook

Kojo ska kunna köras på web, men är det överhuvudtaget möjligt på en chromebook.
Om det går isåfall hur går man tillväga?

Kojo på en chromebook by Ann-Catherine Sjöberg (guest), 12 May 2017 06:55
lalitplalitp 05 Feb 2016 18:31
in discussion Kojo / Support » Kojo in DiDPI monitor

I have started to play with this, and I have a new Kojo-Web build out there ( Let me know if you see any font size improvements with this build.

by lalitplalitp, 05 Feb 2016 18:31
Re: Msi-file
lalitplalitp 24 Nov 2015 05:50
in discussion Kojo / Support » Msi-file

Sorry, we currently only have an exe installer. Is there a problem with using the exe installer? Or is it an IT policy thing?

Re: Msi-file by lalitplalitp, 24 Nov 2015 05:50
AnnP (guest) 23 Nov 2015 17:33
in discussion Kojo / Support » Msi-file

I would like to use Kojo with my pupils at school. Our IT-support wants a msi-file so that they can install Kojo with UpKeeper. Can anyone help me to find a msi-file?

Msi-file by AnnP (guest), 23 Nov 2015 17:33

import javax.swing.WindowConstants

DISPOSE_ON_CLOSE is defined in WindowConstants. JFrame implements WindowConstants, but DISPOSE_ON_CLOSE is not visible via JFrame in Scala (can't remember why off the top of my head).

Re: javax.swing question by lalitplalitp, 22 Oct 2015 15:45
javax.swing question
Anthony (guest) 22 Oct 2015 13:35
in discussion Kojo / Support » javax.swing question

I'm goofing around using Kojo to explore different things, and wanted to explore Swing. Having a problem because Frame.DISPOSE_ON_CLOSE is claimed not to be a member of java.swing.JFrame? No problem with EXIT_ON_CLOSE but I don't want to use that, because Kojo gets killed every time I close the window.

import java.awt.Graphics
import java.awt.image.BufferedImage

import javax.swing.JComponent
import javax.swing.JFrame

val frame: JFrame = new JFrame("Fractal")

Results in:

Error[9,39]: value DISPOSE_ON_CLOSE is not a member of object javax.swing.JFrame

I realise Kojo isn't necessarily meant to be used in this way, but for my better understanding, I am curious why DISPOSE_ON_CLOSE doesn't show up!

javax.swing question by Anthony (guest), 22 Oct 2015 13:35
samyem (guest) 20 Oct 2015 12:48
in discussion Kojo / Support » Kojo in DiDPI monitor

Both of these IDEs have customized themes; netbeans is closer to the default windows look and feel but it is not the standard one that ships with Swing.

by samyem (guest), 20 Oct 2015 12:48
lalitplalitp 17 Oct 2015 14:22
in discussion Kojo / Support » Kojo in DiDPI monitor

Does Netbeans use the 'Windows Look and Feel' on Surface Pro? And Intellij IDEA?

by lalitplalitp, 17 Oct 2015 14:22
samyem (guest) 15 Oct 2015 01:41
in discussion Kojo / Support » Kojo in DiDPI monitor

Surface Pro 3 is 216 PPI, while the new Surface Pro 4 and Surface Book are 267 PPI. I noticed that the newer Netbeans is a bit better at handling high DPI, so Kojo may be able to leverage some of it perhaps?

by samyem (guest), 15 Oct 2015 01:41


Will investigate as soon as I get access to a high DPI monitor. What's the DPI/Resolution on Surface Pro 3?

- Lalit

Re: Kojo in DiDPI monitor by lalitplalitp, 12 Oct 2015 17:44
Kojo in DiDPI monitor
samyem (guest) 10 Oct 2015 13:09
in discussion Kojo / Support » Kojo in DiDPI monitor

Running Kojo under high DPI monitors like Surface Pro 3, the UI appears too small to be usable and the text size used in the editor and menu are tiny and unusable. Other Java programs like IntelliJ appears to respect the system text scale better; is it possible for Kojo to adapt the UI for the high DPI screens?

Kojo in DiDPI monitor by samyem (guest), 10 Oct 2015 13:09

FYI, Scala uses integer division from the Java world.

by lalitplalitp, 02 Aug 2015 05:13
Darin Lee Murphy (guest) 01 Aug 2015 21:13
in discussion Kojo / Support » Problem with the Scala Tutorial and perhaps Kojo itself.

This is an update on the above issue. I think I figured out what's wrong with Kojo/Scala. In the expression 3.5*9.4+7/5 the 7/5 isn't being converted into a floating point or real number before it is added to product of 3.5*9.4. This can be illustrated in the following script:

println(3.5*9.4+7/5) // Returns 33.9
println(3.5*9.4+7.0/5) // Returns 34.3 which is the correct product!
println(3.5*9.4+7/5.0) // Also returns 34.3 which is also correct!

So it appears that the 7 isn't being converted into a float. I can live with this bug, but just wanted to let everyone know that to be on the safe bet not to mix floats with integers until this gets correct. Take care now and have a good day!

by Darin Lee Murphy (guest), 01 Aug 2015 21:13
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