Computing Support
Computing Support
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Mathematical Sciences Department Computing Facilities FAQ

Beginner's questions

What do I do if my file does not print?
How do I create a good looking pdf file starting from a dvi file in Linux?
How do I know that a pdf file will look good on any platform?
How can I visualize data in Linux?
How can I create movies in Linux?
How can I view movies/listen to music on qwe or math computers?
How can I create mp3's in Linux?
How can I edit a sound file?
How can I use the scanner from Linux?
How can I burn CDs/DVDs from Linux?
What command should I use to do "that task"? How should I use this command?
How can I find more about computers?
How do I keep running a long job on the parallel cluster if I need to logout?
How do I restrict access to parts of my website?
How do I convert my pine addressbook to be available in thunderbird/seamonkey?
How do I convert my ical .calendar file to be compatible to Sunbird, Google Calendar, Apple iCal, or Outlook?
How can I print text documents or e-mail messages from pine?
Why some pdf documents printed by acroread or okular on a duplex queue would come out one-sided?

I do not want my work and future to depend on a company

What matlab/maple/mathematica clones developed by the scientific community are available?
What spreadsheets are available in Linux?
What word processors are available in Linux?
How can I create slides or PowerPoint-type presentations in Linux?
How can I see/edit/print Microsoft Word/Excel/Powerpoint in Linux?

Maintaining your own computer

What's the IP setup for a .math computer in Wean Hall?
How do I configure the public Math printers in Wean Hall?

Before you leave CMU

How do I forward my e-mail?
How long will my account last after I'm leaving?

What do I do if my file does not print?

Please see the debugging procedure here.

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How do I create a good looking pdf file starting from a dvi file in Linux?

A dvi file can be transformed into a postscript file optimized to be converted to pdf using the "dvips -Ppdf" command and then the postscript file is transformed into a pdf file using the "ps2pdf" command. Alternatively, the dvi file stage can be skipped altogether by using pdflatex directly on the tex file.

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How do I know that a pdf file will look good on any platform?

Rendering pdf files depends on the fonts used by the file and if those fonts exist on the reader's computer. The solution to this is using "Type I" fonts which are actually included in the file itself, are scaling well, and will be rendered correctly and nicely by almost any pdf reader.

To see what type of fonts are used in a certain pdf document, open the document in the Acrobat Reader ("acroread" command in Linux), and open the following menu: "file" -> "Document Info" -> "Fonts".

The Linux procedures described above generate pdf files containing only "Type I" fonts.

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How can I visualize data in Linux?

Good packages for graphs, interactive graphs, animation:

    • gnuplot - 2D and 3D graphs
    • dx - professional scripting language oriented visualizing application including 2D and 3D graphs, animation, lots of options and refinement to define interactive features.
    • xgraph - nice graphs from data files
    • grace - WYSIWYG 2D interactive plotting tool; docs and examples in /usr/local/grace

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How can I create movies in Linux?

Movies can be created or transcoded by ffmpeg. For example, "fmpeg -r 3 -f image2 -i name-%05d.jpg name.mp4" will combine jpg frame files name-?????.jpg into a movie name.mp4 on a refresh rate of 3 frames per second.

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How can I view movies/listen to music on qwe or math computers?

Each qwe computer and most of the math computers have sound cards. If speakers are not available, the output connector behind the computer can be used with user-provided headphones. Most multimedia files can be played with mplayer (or gmplayer if a GUI is desired) and vlc.

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How can I create mp3's in Linux?

A very good application to transform wav files in mp3 is "lame". If you are handling wav and mp3 files on the qwe computers, please keep them inside a folder named "tmp" that can be created in your home directory, such that the large sound files will not clog the backup server.

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How can I edit sound in Linux?

A nice sound/waveform editor/filter for wav files is "audacity".

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How can I use the scanner from Linux?

Operation of the existing scanners is described here.

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How can I burn CDs/DVDs from Linux?

A good application with self-explanatory GUI is k3b.

NOTES:

    • Multi-session CDs: a way to add data to a CD/DVD is to use the multi-session mode (widely used on music CDs). For compatibility reasons we don't recommend this mode for data CDs.
    • Encrypted CDs/DVDs: some commercial game/music/movie media are protected (scrambled in some way including weak encryption, portions of I/O errors on the media, etc) to make them illegal to be copied (see DMCA). Please do not copy them.
    • Compatibility issues: Some CDplayers cannot play CDRW, others cannot play but wav files (no mp3s), some DVD players cannot play but DVD-R media. Please test and use the right media for your equipment.

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What command should I use to do "that task"? How should I use this command?

On Unix/Linux computers use the command "apropos keyword" to find a list of commands which may do things described by keyword; then use "man command" to find out what does the command do. If you are familiar with emacs, "info command" may offer a nicer interface that can be browsed.

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How can I find more about computers?

A general purpose course 21-765. Introduction to Parallel Computing and Scientific Computation (http://www.math.cmu.edu/%7Eflorin/M21-765/) is offered each Spring Semester by the Math Sciences Department.

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How do I keep running a long job on the parallel cluster if I need to logout?

You can start the job through "nohup". In that case the job will run in background and standard output goes into a file named nohup.out. The job doesn't quit at logout.

Another solution is to use "byobu" to start a terminal. After the job is started, the bypbu session can be detached by pressing F6. To re-attach to the byobu session, just start byobu inside any remote session.

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How do I restrict access to parts of my website?

The apache webserver allows access restriction to files in a directory based on a set of credentials. To use that, a file named .htaccess should be created inside the directory.

For password based restriction, the file .htaccess should have the following structure:

   AuthUserFile /export/home/math/user/directory/.htpasswd
   AuthType Basic
   AuthName "name"
   Require valid-user

This will allow the access of the user "name" with the password specified in /export/home/math/user/directory/.htpasswd. To create or change the password, please use the "htpasswd -c -m name /export/home/math/user/directory/.htpasswd" command.

It is possible to restrict access to directories based on the andrew credentials by using shibboleth. In that case, the .htaccess file should contain:

   AuthType shibboleth
   ShibRequestSetting requireSession 1
   Require shib-user ~ ^.+@andrew.cmu.edu$

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How do I convert my pine addressbook to be available in thunderbird/seamonkey?

Thunderbird/seamonkey are using the ldif format for storing the addressbook.

An imperfect converter can be found here.

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How do I convert my ical .calendar file to be compatible to Sunbird, Google Calendar, Apple iCal, or Outlook?

Current calendar applications use the ICS file format for storing their data.

An imperfect converter can be found here.

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How can I print text documents or e-mail messages from pine?

Some of the printers will not print text documents properly when they are sent directly to the printer via the lpr command. Please use one of the mpage or enscript commands instead. These commands transform text into postscript and offer useful options for arranging the result in page (page orientation, multiple pages of text on a sheet of paper, etc - please see the manual pages). A text file "file.txt" can be printed at the queue "queue" using enscript by issuing the following command:

"enscript -P queue file.txt"

Some applications handling text documents, like "pine", use lpr behind the scenes to print the text files. Please configure "mpage" and "enscript" into those applications as well if needed.

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Why some pdf documents printed by acroread or okular on a duplex queue would come out one-sided?

Even if the default settings of the queues starting with a "d" is duplex, this can be overwritten by the application or by the document itself. If an application prints one-sided on a duplex queue, please go to the properties of the queue inside the application's printing window and make sure that the right mode of duplex is selected.

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What matlab/maple/mathematica clones developed by the scientific community are available?

scilab (developed at INRIA) or octave.

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What spreadsheets are available in Linux?

gnumeric or the spreadsheet application in OpenOffice (command "soffice"). The OpenOffice spreadsheet handles most Excel files.

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What word processors are available in Linux?

The power word processor for publishing is Latex.

For fans of WYSIWYG applications:

A nice and fast word processor is "abiword". It doesn't have as much features as Microsoft Word, but in the end who is using at least half of those. It can read and create MSWord documents.
Another more feature-rich word processor is the one which comes with the OpenOffice suite (command "soffice"). It can also read and create MSWord documents.

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How can I create slides or PowerPoint-type presentations in Linux?

One solution (the professional one) is to use the "slides" class in Latex. Or, for nicer graphics, you can use the prosper extensions to Latex (documentation in /usr/share/texmf/tex/latex/misc/prosper).

Other solution: A PowerPoint alike slide creator came with the OpenOffice suite (command "soffice").

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How can I see/edit/print Microsoft Word/Excel/Powerpoint in Linux?

Some of those documents can be handled by the corresponding applications from OpenOffice (command "soffice"). Some Word documents can be handled by the "abiword" word processor.

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What's the IP setup for a .math computer in Wean Hall?

Gateway: 128.2.112.1
Netmask: 255.255.248.0
Broadcast: 128.2.119.255
Nameservers: 128.2.1.10, 128.2.1.11

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How do I configure the public Math printers in Wean Hall?

Public math printers in Wean Hall are listed here. They can be configured from any networked device belonging to Math Dept personnel. To collect the printout, you need to get a key to the print rooms from the main office, room 6113.

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How do I forward my e-mail?

On the qwe and Math private computers:

    • create a .forward file in the home directory, to start forwarding; the file should contain the address to be used for forwarding, or a list of addresses separated by commas on the same line;
    • delete the .forward file to stop forwarding.

For the andrew mail:

    • login to an andrew computer and issue the command "forward new_address", where new_address is the address to be used for forwarding, or a list of addresses separated by commas; the forwarding will start in up to 48 hours;
    • login on an andrew computer and issue the command "forward -z"; the forwarding will stop in up to 48 hours.

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How long will my account last after I'm leaving?

The accounts on the qwe cluster and on the Math private computers will last for as long as you need to safely move your files. Please talk to Florin about this, before you leave.

The andrew account policies are rapidly changing. Please contact the Help Desk to find out more.