ECJ Howto Part 1

Part 1 of how to use the Evolutionary Computation for Java framework

Category:

Science & Technology

Tags:

• ecj
• java
• ec
• evolutionary
• computing

[mysticyx]

When I follow your steps, (except for using more recent versions, namely ecj 20 and jfreechart 1.0.13) I get a red X at 7:30 (video time). The error is: "Acces restriction: The type Hashtable is not accessible due to restriction on required library C:\... The class file that's causing the error is ec.app.bbob BBOBenchmarks.java.

I hope you understand. Do you know how I can fix this? Or at least tell me what I've done wrong? Google doesn't resolve anything.

[autophile06]

@mysticyx Hmm, it looks like ec.app.bbob.BBOBenchmarks.java includes this line:

import com.sun.org.apache.xalan.inter­nal.xsltc.runtime.Hashtable;

As far as I can tell, it isn't actually used. Maybe delete that line from BBOBenchmarks and recompile. Then try again.

[PizzaIdiot4]

Hi,

I will be working on ECJ this semester for an AI class so thank you for posting this useful video. I have followed all the steps you are indicating for running the example in Eclipse but it's not working :( I am getting the error message "Could not find the main class. Program will exit." although I did add ec.Evolve as the main class. Do you know what's happening?

Thanks again for your help :)

[autophile06]

That means Eclipse can't find your classes. Anything could be wrong, but here are a few things to get you started:

Make sure your project is highlighted in the Package Explorer on the left. Go to the project properties, Code Build Path and make sure Libraries and Source tabs show the correct paths. Make sure that under your project in the package explorer, there is a folder with ecj16 (or 17, now, apparently), and under ecj16/17 is a folder called ec.

Other than that, it could be anything.

[dvunkannon]

You should also change the default for where Eclipse puts the .class files so that it puts them in the source folders. This will let the ECJ Console app run as expected.

[autophile06]

Well... you could. But I prefer my class files in a separate directory than the source files :)

[PizzaIdiot4]

Nevermind... I fixed it.

Are there any good beginner level tutorials on using GUIs with ECJ with JFreeChart? If so can you recommend any?

[dvunkannon]

OK, but then I think you have to move all the button bitmap files out of the distribution sourse folders and into your bin folders. If you do a tutorial on using the ECJ GUI, I'm sure these points will come up! Thanks for two great segments, I'd love to see more.

[erenerenay]

Great explanation.

We want more... :)