Frequently Asked Questions



1. Downloading Starlogo

StarLogo won't run on my Mac. What should I do?

Make sure you have the latest version of Apple's Macintosh Runtime for Java (2.2). You can download it here.

StarLogo still won't run on my machine. What should I do?

Send an email to bug-starlogo@media.mit.edu and provide details of your configuration and what you've tried to do to make it work.

I've been having trouble downloading StarLogo from your web site. What should I do?

You should try using our ftp site if you have been having trouble downloading from our website. You can ftp to chelona.media.mit.edu The username is sldist and the password (case sensitive) is MrSabb StarLogo is in /pub/starlogo.

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2. Running Projects

Why doesn't my project work in the new version of StarLogo (version 2.0)?

There are two possible reasons for your old project not working in the new version of StarLogo. The first reason is that the command for pressing buttons from the command center has changed. Before you only had to enter the name of the button. For example, if your button was named "go", you simply had to enter "gobutton"; however, in the new version you will have to enter "startgobutton". In other words, you have to append the word "start" to the beginning of code calling for pressing buttons. This may have to be done manually in old projects and then resaved.

The second reason your project may not work in the new version of StarLogo is that version 2.0 implements tighter error checking for code in the command center. One of the most common errors is the code: "(3 +5)". This error used to be ignored in the old StarLogo. However, in the new version, this error will stop a project from compiling properly. Make sure your old code is free from these errors.

Why doesn't the new project I downloaded work on my StarLogo?

If you have StarLogo version 1.2.2, it may not be able to compensate for some of the new features in StarLogo version 2.0, and this may be what is causing you errors in the new project. Get the newest version of StarLogo at the download site.

Why does StarLogo run so slowly and flicker?

In Windows ME, Windows 2000, and Windows XP pointer shadows can cause StarLogo to run slowly and flicker with certain mouse cursors. To stop this effect, simply go to your Mouse Control Panel and uncheck the 'Enable Pointer Shadows' option. To do this, go to your Start Menu, Settings Icon, Control Panel. Select the Mouse icon and go to the Pointers tab in the window. At the bottom left, uncheck the "Enable Pointer Shadows" box.

StarLogo only prints blank pages. How do I fix this?

In Windows, printing does not work properly at a 16 bit Color depth. In the Display Properties Control Panel, change your Colors to either 256 Colors or 32 bit. To do this, right click on your desktop and select Properties. Go to the Settings tab of the window, and at the bottom left, change your color depth to something other than 16 bit.

Why doesn't project X from my old MacStarLogo run anymore?

StarLogo is similar in many ways to MacStarLogo. However, it stores projects in its own unique format. In addition, there are language differences between StarLogo and MacStarLogo that prevent projects from being saved in one program and run by the other. If you would like to translate a MacStarLogo project for use in StarLogo, open it in StarLogo (or a text editor). Some changes will be necessary before it will run. Consult the StarLogo documentation to find out more about how to create projects in StarLogo. If you are having difficulty translating your projects into StarLogo, you can email bug-starlogo@media.mit.edu with questions.

Why can't I use templates in StarLogo when running on Mac?

Our template code is too naive and can not read files with macintosh carriage returns. Once we've rewritten it, we will support templates on Macintosh.

I would like to use sound with my projects. Where can I find a sample project which demonstrates how to do this?

Sounds have been disabled in this release of StarLogo due to the non-standard implementation of Java on different operating systems.

How can I run a StarLogo project on a web page?

When you are ready to save your desired project, choose "Save Project as Web Page" from the File menu. You will first be prompted to save the StarLogo version of this project (a .slogo file) and then to choose a name for the .html file. To allow the applet to be run over the web, place a copy of this starlogo.jar, your project (.slogo) file, and your web page (.html) file all in the same directory, and then load the .html file into your browser. On a Mac, the starlogo.jar file can be found in the StarLogo folder. Windows users can find it inside the Internal StarLogo files folder. We have confirmed that this applet will run on PCs using Internet Explorer and Netscape. If you don't have the Java plug-in for Netscape, your browser will prompt you to download it when you try to load the applet. If you're using a Mac, you will need to use Internet Explorer and MRJ 2.2.5 or later.

What are valid names for buttons?

When you bring up a Button Dialog to create a new button, the "Name" field can be filled with any string of characters. If you have spaces (" ") in this name, they are converted to the dash character ("-") internally. This has two implications. First, it means that you can allow a procedure to call a button by prepending the word "start" to the button name and stop a button by prepending the word "stop" to the button name. For example,

to go
myfirstbutton ;the "Name" field of this button contains the string
"myfirstbutton"
startmy-second-button ;the "Name" field of this button contains the string
"my second button"
stopmyfirstbutton
end

One more thing. You naming conflicts may occur in the internal code if any of your procedure names begin with "start". Avoid naming procedures in this manner.

How do I resize the graphics canvas?

If you click in the white area of the StarLogo window, and then drag your mouse over the black graphics canvas, the canvas should become selected (little black squares will appear at the corners, and some sizing information will appear on the grey toolbar at the top). You can use the black squares to resize the canvas (click and drag), and you use the slider which appears in the toolbar to change the size of the patches.

I'm having trouble opening StarLogo files over a network. What's wrong?

If you have StarLogo 1.2 installed on your local computer and try to double-click a project stored on a computer over the network, StarLogo will try to load a file with a UNC path (UNC paths are path names of the form \\server.name.edu\somedirectory\myfile.slogo). However, UNC paths are not completely supported by Windows, so if you try this StarLogo will give you an error message that the file is not readable. Opening the StarLogo application locally from your Start Menu and then choosing "Open File..." from within StarLogo will allow you to access the network file without a problem.

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3. Macintosh Information

I have a Macintosh. Which version should I use?

StarLogo requires Mac OS 8.1 or higher, while MacStarLogo will run on a Mac IIfx or better running Mac OS 7.5 or higher and with at least 256 colors. The features of the two programs are slightly different, so you might want to try StarLogo before making a final decision. For more information, see the Notes section.

I still want to use MacStarLogo.  Where can I find information on it?

The MacStarLogo website has moved to http://el.www.media.mit.edu/projects/macstarlogo

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4. Other

I've read about several other StarLogo projects from Mitchel Resnick's book Turtles, Termites, and Traffic Jams but I can't get any of the code in his book to run in StarLogo. What should I do?

If you are planning on using code from Professor Resnick's book, it will require several modifications in order to run under StarLogo. In particular, you will need to separate his procedures into separate observer and turtle procedures, in much the same way as you would have to if you were porting a project from MacStarLogo to StarLogo. Also, the daemons (demons) in Professor Resnick's book no longer exist; they have been replaced by forever buttons. Consult the StarLogo documentation to find out more about how to create projects in StarLogo.

What other StarLogo-type programs exist and where can I find them?

StarLogoT has been developed at Tufts University and Northwestern University. StarLogoT was built on top of MIT's MacStarLogo, adding some new capabilities and interface features.

NetLogo is a multiplatform complexity modeling and simulation environment that shares many features with StarLogo.

Agentsheets is a commercial product that lets end-users build a wide range of applications that include interactive simulations, games, and intelligent web agents through a graphical user interface.

For more advanced research applications you can also check out Swarm, Ascape, and Repast.

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5. Known Bugs

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