Department of Computer Science

Machine Learning Research Group

University of Texas at Austin Artificial Intelligence Lab

Machine Learning Research Group's Internal FAQ

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About this FAQ

  • Technical Tips
    • Also check out the Group Tutorials

    • Emacs changes the group and the permissions on any file that I edit. How do I prevent this?

      Add the following lines to your .emacs file:

      (setq 
            backup-by-copying nil 
            backup-by-copying-when-linked t
            backup-by-copying-when-mismatch t)
      

    • Group CVS directory

      The group CVS repository is in /u/ml/groupcode/cvsroot. If you start projects there, please be sure to change the default group to lunar by executing 'chgrp -R lunar dir' on every dir you create. All CVS documentation is located here.

      For more information, visit our Mini CVS tutorial page.

    • Policy for software installation in the group directory

      There are two things to keep in your mind when you put something in the /u/ml directory.

      • Have all the directories in /u/ml/software be u+rwX and g+rwX, but o-rwX. This would allow group members to make modifications to the installations e.g. making minor (documented) changes to Makefiles, gunzipping files unused for a long time, etc. At the same time, it would not provide such access to the general public.
        It can be achieved for directory "foo" and all its subdirectories by using the command:

        chmod -R ug+rwX,o-rwX foo

      • Have all the directories be owned by "lunar".
        It can be achieved for directory "foo" and all its subdirectories by using the command:

        chgrp -R lunar foo

    • How do I change my default group to lunar or fix all files in a directory to a group?

      • To fix all files in a directory to a group we can use 'chgrp -R lunar *'.

        We can also set the setgid bit for /u/ml and its subdirectories. Then every new file and subdirectories created inside will belong to lunar by default. To set the setgid bit, use 'find -type d | xargs chmod g+s'.

    • Checking CS email from Web

      There is a way to check CS emails from web using UT's webmail facility. This is probably useful from Internet cafes which don't let you telnet etc..

      1. Go to https://webmail.utexas.edu/
      2. Give your UT EID and password
      3. In the new page, under "Custom Login" give your CS login and password, write "imap.cs.utexas.edu" for server and "Inbox" for Folder.

    • I get the following URL exception error while running weka.gui.explorer.Explorer in VNC (or from an X-shell running on home computers). How do I fix it?

      goya.cs.utexas.edu 101> java weka.gui.explorer.Explorer
      
      Warning: No configuration property found in
      weka/gui/GenericObjectEditor.props
      for weka.experiment.InstanceQuery
      Warning: Can't find public property editor for property "options" 
        (class "[Ljava.lang.String;"). 
      Skipping.
      Setting numeric precision to: 10
      Setting axis colour to: green
      Setting background colour to: black
      Setting attribute bar colour to: black
      Displaying attribute bars
      Uncaught error fetching image:
      java.lang.NullPointerException
            at sun.awt.image.URLImageSource.getConnection(URLImageSource.java:99)
            at sun.awt.image.URLImageSource.getDecoder(URLImageSource.java:108)
            at sun.awt.image.InputStreamImageSource.doFetch(InputStreamImageSource.java:251)
            at sun.awt.image.ImageFetcher.fetchloop(ImageFetcher.java:168)
            at sun.awt.image.ImageFetcher.run(ImageFetcher.java:136)
      goya.cs.utexas.edu 102> exit
      
      • You might want to change the CLASSPATH. Be sure to incude the current directory, denoted by a period (.) in your classpath, as in: -classpath .:classes. Click here for more information on this problem.

    • For those of you who are tired of seeing Java flush the annoying "Couldn't get file lock" exception when running Weka, the workaround is to run Java with this command-line option:

      -Djava.util.prefs.syncInterval=2000000
      
      (e.g. java -Xmx500m -Djava.util.prefs.syncInterval=2000000 
      weka.gui.experiment.Experimenter)
      
      Here is the bug description (registering needed). Sun labeled it fixed in 1.4.1, but this is clearly wrong. Hopefully they will fix it in the next release. Here is the page that explains the workaround.

    • How to get a clean pdf file

      Please use "dvips -Ppdf" when you convert your .dvi file to .ps file.

    • How to produce a pdf file with embedded fonts that does not contain Type 3 fonts?

      Instructions from AAAI

      Suppose your document is named paper.tex. Run the following commands:
      dvips -Ppdf -G0 -tletter paper
      ps2pdf -dPDFSETTINGS=/printer -dCompatibilityLevel=1.4 -dMaxSubsetPct=0 \
        -dSubsetFonts=false -dEmbedAllFonts=true -sPAPERSIZE=letter paper.ps
      

      Old Instructions


      The following commands should be used:
       
      dvips -f -Ppdf -G0 < file.dvi > file.ps
      ps2pdf13 -dPDFSETTINGS=/printer file.ps
      

      To check the fonts of your pdf file, you can do one of the following:

      • Open the pdf file with acroread and choose File, Document Properties, Fonts tab. Embedded fonts will be listed as "Embedded." Fonts that are not embedded will not be marked in any way.
      • Use the command
        pdffonts file.pdf
    • How to combine several pdf files into one pdf file?
      Suppose you have two pdf files a.pdf and b.pdf and you would like to combine them into combined.pdf. The following command does the trick:
      gs -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=combined.pdf -dEmbedAllFonts=true \
        -dSubsetFonts=false -dBATCH a.pdf b.pdf
      
      In addition, it forces all fonts to be embedded.

    • How to convert a powerpoint slide (or figures in a pdf file) into an eps file to be embedded in your latex document?

      Since you may find creating figures easier using powerpoint or you want to use existing slides in your document, follow these steps.

      • Save the powerpoint slides into a pdf (print -> save as PDF)
      • Open the pdf using gimp
      • Select to import the page you want
      • Use Tools->Selection Tools to perform any cropping (NOTE: Use Image->Crop to Selection instead of Layer->Crop to Selection)
      • Save the cropped figure as an eps file
      To use a figure in an existing pdf file, simply follow the same steps starting with opening the file using gimp.


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    Last modified: December 21, 2010 (Always under construction)