Atom Graduate Physics Laboratory Handbook: Computer Facilities
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Computer Facilities

Overview

IBM (or IBM compatible) microcomputers are available for data collection and analysis. Most of these machines are connected to the Campus Ethernet System. They are available in the Graduate Laboratory's experimental areas and computer room PHY-3309, and i n the Department's Microcomputer Laboratories (rooms PHY-3115 and -3120). These computers have broad capabilities in both the programs already written and in the programs students may develop in QuickBASIC, Turbo PASCAL, C++, FORTRAN, and Assembler.

The programs available include:

  1. Origin © - a copyrighted scientific graphing software with powerful fitting capabilities for both peak location and arbitrary function fitting.
  2. SciWord © - a copyrighted Windows document processor. This program is called Scientific Word/Scientific Workplace ©. It permits the preparation of papers in standard APS article format.
  3. PCT4 - a public domain program enabling the transfer of data from various equipment to the PC.
  4. PLT - a program to convert and graph data. Within this program MultiChannel Analyzer data can be reformatted into standard Teaching Laboratory Format (that is, XY) to prepare it for use within the structure of the following programs.
  5. LINREG - a linear regression program for fitting data to various functions, providing a broad range of statistics.
  6. ANALYSIS - a program capable of fitting Lorentzians and Gaussians and providing goodness of fit measures, 2 and 2/, where  is the number of degrees of freedom.
  7. ACQUIRE - a LabView program to acquire data from internal data acquisition and digitizing boards and display that data graphically. A full operator's manual is found below in the section on ACQUIRE.
  8. TELNET - here a Windows  program for communicating between unix computers. Some simple instructions are to be found below in the section on "TELNET".
  9. FTP - the standard NCSA FileTransferProtocol (FTP) program which enables the moving of files from one computer to another rather quickly and accurately without the need to copy them to floppy disks. Abbreviated instructions are to be found below in the section on "FTP".
  10. LABVIEW - a programming interface for making Virtual Instruments.  It allows very convenient programming of the Grad Lab's GPIB interfaced instruments with Windows capable programs.  It offers many graphical displays capable of showing the progress of an experiment with live graph windows. See the section below on "Computer based instrument control".
Remote access for on-line computing is available on campus (in the Graduate Laboratory Computer room, PHY-3309, the OWL (the Department's Open Workstation Laboratory, PHY-3115 and -3120), and the WAM (the University's Workstati ons At Maryland facilities) rooms throughout campus. Beginners and persons who simply do not wish to fight FORTRAN's less forgiving nature should consider using QuickBASIC or Turbo PASCAL. These latter two can be learned in a few hour s by the use of tutorial packages, which are integral to the programs. Manuals for these computer languages are available in our Library (PHY-3333) and the Computer Room (PHY-3309).

ACQUIRE

The TAKEDATA program has been replace by a Windows program called ACQUIRE.  The interface to the A/D card has been modified so that  to operate the A/D card  ACQUIRE must be used.  There is a shortcut to start it on the Windows Desktop.  General instructions for using ACQUIRE   are at the here.

Program to Transfer Data from MCA to PC

This appendix describes the use and operation of the program PCT4, which enables the transfer of data from the Laboratory's MultiChannel Analyzers to the computers located throughout the Laboratory. PC's, to which data are to be transferred from MCA's, have a coaxial cable attached to their serial ports. This cable terminates in a BNC connector. In addition, there is a cable with a multipin connector (peculiar to the particular MCA model, eith er Tracor RM-1704 or Inotech IT-5200) also terminating in a BNC connector. To transmit data from an MCA to a PC these cable must be connected. After data have been collected on the MCA, proceed as follows:
  1. Terminate data acquisition on the MCA; i. e., toggle the ACQ button on the MCA, placing it in stop mode.
  2. On the PC enter the command PCT4. This will run a program stored on the C: drive of the PC in the subdirectory \pct4. When the program begins it will display a summary of its commands. This summary is always availabl e and may be accessed by pressing the HOME key.
  3. From the command summary it will be noted that to have the PC receive data from the MCA enter the Receive File command by pressing the ALT and R keys together (or by pressing the PgDn key). The PC will respond with " specification:". 
  4. Give the filename in which the data are to be stored on you own disk (e. g., a:myfile.dat ). You store data on the PC's hard drive at your own risk; data stored on C: may not be there the next time you need it.
  5. Press the I/O button on the MCA. The program will confirm that it is receiving the data by displaying these data on the PC screen. The MCA's cursor will move slowly across its screen as the data are transmitted. When data transmission is complete, the MCA screen returns to its normal mode and the data no longer scroll on the PC display. Enter ALT-R or PgDn again to end the receive data mode.
  6. The data are now stored on the PC in the file and on the disk drive you specified in Step 1 above. It is a good idea to view the data paying particular attention to any irregularities such as missed channels or non-numeric characters whi ch can cause trouble later on. To view data enter ALT-V. The filename to view will be requested as above (i.e., the PC will respond with"specification:"). Enter filename exactly as entered before. Note the bad data chann els. Then either retransmit the data or use the MCA cursor control to read out the individual channel data for later manual data entry. To modify errant data, use a text editor such as the Norton Editor or the DOS EDIT, which are accessible by entering at the DOS prompt the command NE or EDIT after exiting PCT4.
  7. Exit the data transmission program PCT4 by ALT-X. Modify any bad data before proceeding.
  8. Run the plotting and reformatting program PLT or PLOT. This is necessary because the MCA's output data in a relatively useless format. Most data analysis and plotting programs prefer the data in X-Y format. Menus allow the selection of various options; Enter 1 to reformat or 2 to plot. Data which come directly from the MCA's must be reformatted. The reformatting menu requests the type of MCA used to acquire the data. Enter the selection number presented in the menu for the specific MCA used. The next request is for the filename of the data to be reformatted and the reformatted filename. Note: enter the filename with the drive designation (e. g., A:myfile.dat) but with a different extension (e. g., A:myfile.ref). The program indicates that reformatting is in progress and is complete (indicating "Done"). The first menu is now redisplayed. A simple plot of the reformatted data can now be displayed.
  9. Follow the screen instruction to view a graphical representation of the data. When you are satisfied with your data, you may now proceed to data analysis with the programs LINREG or ANALYSIS.

Telnet and FTP

The well-known NCSA Internet routines, TELNET and FTP are used to communicate between computers and are available on most Graduate Laboratory computers.

Connecting To Remote Computers With Telnet

The telnet program is used to logon to other computer systems. Telnet has a wide variety of features that allow you to add sessions, navigate between them, print graphics files from your WAM account to the printer in the lab, sc roll the screen to peek at your previous commands, and many more.

To connect to another computer, at the DOS prompt, enter

telnet hostname
where host-name is the Internet address of the remote computer. (If host-name is omitted the computer on which the command was entered will become an ftp server, which permit the transport of files from one computer to another. See the section on ftp below.)

Internet addressesInternet addresses or host-names have the form userid@system.typ , e. g., zwizwi@delphi.umd.edu . Addresses ending with edu are university addresses, while com denotes commercial, org denote s general organizations, and gov denotes government. After logging on, entering Alt-H displays a help screen that lists the telnet commands for using the various features of telnet , such as Alt-A for adding a session and Alt-M for activating the mouse.

Transferring Files Using FTP

With the command ftp , or Alt-F, you can transfer files between any computer and a remote account, or from one account to another. You can also use anonymous ftp to obtain public domain software.

To transfer a file between the PC disk and a Unix account or ant ftp server, use the following steps:

  1. Type ftp at the DOS prompt to get the ftp prompt. ftp has a lot of commands in it: type ? to have a peek at them, or proceed to step 2 if you'd rather learn about them later.
  2. Type open host-name, (e. g., open WAM).
  3. You will be prompted for the login name and password.
  4. Type get filename or put filename to transfer if from the disk or to the disk, respectively. If you transfer from Unix, the DOS destination will be the current directory.
  5. Type bye to quit ftp.
To transfer a file from one Unix account (say delphi) to another (say WAM), logon to your delphi account and type ftp at the prompt. Then follow steps 2 to 5 described above.

ftp Commands

Type ? at the ftp prompt or, if you are on a UNIX computer type man ftp at the Unix prompt for more information. ftp help is somewhat terse.

Some useful commands are:

  1. pwd (present working directory) indicates the active directory on the remote computer.
  2. ls provides a listing of the contents of the current directory on the remote computer, but in the standard UNIX format.
  3. dir provides a listing of the contents of the current directory on the remote computer, but in the standard DOS format.
  4. lls same as ls but on the local computer.
  5. cd change directory on the remote computer. This command must be followed be the directory name, as for example, cd user.
  6. lcd change directory on the local computer. This command must be followed be the directory name, as for example, lcd user.
  7. binary enables the transfer of a binary file.
  8. hash during file transfers a # is displayed for each 1024 kbytes transferred.
  9. get moves a file from the remote to the local computer. This command requires the argument filename, as for example, get test.day.
  10. put moves a file from the local to the remote computer. This command requires the argument filename , as for example , put test.day.
  11. mget moves many files from the remote to the local computer. This command requires the argument filename, as for example, mget test.day.
  12. mput moves many files from the local to the remote computer. This command requires the argument filename, as for example, mput test.day.
  13. ! shells out to the operating system. This symbol is commonly referred to as a "bang". To return to ftp from the operating system type exit.
  14. bye stop or exit from ftp.
 

Computer based instrument control and data collection in Grad Lab

This section was written by Andrew Berkley, August 1999 and is edited and maintained by Robert Gammon.
 

Contents

1. GPIB

Many of the instruments in the Graduate Laboratory have IEEE-488.2 GPIB (General Purpose Instrument Bus) interfaces. This GPIB interface is a mechanism for a computer to control an instrument and read data from it. You may connect any number of instruments to a computer. The instruments are connected to the computer via stackable cables so that one can easily connect multiple devices.

Each device connected to the GPIB bus must have its own GPIB Address. Each instrument provides a different mechanism for setting its address, so see the documentation in the library on the instrument you wish to use.

2. LabVIEW

LabVIEW is a programming environment specifically tailored to make data collection and control of a set of instruments from a computer a straightforward job. Previous to the introduction of LabVIEW most of the interfaces in Grad Lab were written in QuickBasic which provided for very limited real-time data visualization. LabVIEW provides a wealth of tools for presenting data while it is being taken or for reading previously taken data.

For experiments where data taking via GPIB occurs on a regular basis some pre-written LabVIEW programs have been provided to make data taking a comfortable, and pleasant experience. Currently the critical opalescence and ferroelectric experiments have data collection programs written for them.

While these programs make it easy to read data from the devices you should be very careful to understand what the settings on the meter mean and to choose them correctly.

3. Instruments supported

3.1 HP 34401A Multimeters

The HP 34401A multimeters are one of the most common devices in the Grad Lab environment. Thus they are probably the first choice for computer based data collection.

3.1.1 GPIB Address

When you power on the HP 34401A multimeters they display their GPIB address. You may change the address by navigating the menus on the meter by hitting SHIFT, MENU ON/OFF,>>>>, and then using the < and > and and ^ to change the address and then press AUTO/MAN to save the changes.

3.1.2 Resolution

The resolution setting on the meter is the number of digits reported. This can be set from 4.5 to 6.5. The 0.5 digit corresponds to a 1 or 0 at the farthest left position.

3.1.3 Range

The range setting on the meter basically tells the meter where to put the decimal place in the 6.5 digits. That is, if you read a 2 Kohm resistance while on a 200 Kohm scale, you will be wasting two digits of resolution (as the first two digits will be zeros).

Both the range and resolution settings may affect the current the meter uses to measure resistance.

3.1.4 Speed

The speed setting is, as are all features of the meter, described in the HP 34401A manual. Depending on the number of digits of resolution this setting controls how long the meter averages the A/D reading before reporting it. There is a table in the manual which gives the actual times in terms of number of power line cycles (60 Hz).

3.2 Keithley 193 System DMM

The Keithley 193 System digital multimeter provides a wealth of features including filtering and averaging. There is only one of these devices in the lab and it is most often used in to the Ferroelectric experiment monitoring temperature.  If you needs its capabilities, arrange to share with the student dint the Ferrelectric experiment

3.2.1 GPIB Address

The GPIB address of the K193 defaults to 30. Changing it is possible and the procedure is described in the manual though this should be unnecessary.

3.2.2 Filtering

3.2.3 Resolution / Range

Changing the resolution or range of the K193 may also change the current used to measure resistance.   A quick experiment will show the the 2 Kohm scale at 6.5 digit resolution puts too much current through the thermistor resistance themometer causing self heating.  It is better to use 20 Kohm scale.  You can test this when the controller is holding a constant temperature by setting the K193 to different resistance scales and seeing that the resistance read is different.  Differences can be large enough to indicate self heating temperatures of more than 50 mK.

3.3 EG&G 5209 Lock In Amplifier

The EG&G 5209 Lock-In Amplifier is a feature rich lock-in which with its GPIB interface alleviates the need for a separate meter to watch the voltage on the output of a lock-in. Having a computerized interface to it means that there is never a problem with forgetting what the sensitivity of the lock-in was set to. The reading rate from the lock-in is upwards of 100Hz (limited by the lock-in digital interface). Control of all the lock-in features is possible both from the computer or from the front-end while it is running. Care must be taken to write down the filtering and time constant settings as these are not logged by the computer unless you use the ``Save Config'' button to save the configuration (in a non-human readable format) to disk. After saving the configuration you may look at it later by choosing ``Load Config''. While the sensitivity is already taken into account by the output from the lock-in being put in volts referenced to the input, the sensitivity setting also determines how many digits of that result are valid.

The only interface to the EG&G 5209 lock-in is through the Generic Logging program.

3.4 Keithley 485 picoammeter

The Keithley 485 picoammeter is a ammeter which can measure from microamps down to picoamps. The GPIB interface provides for a reading rate of three Hz (limited by the digital interface on the K485, not by the ammeter itself which has a documented rise time of only a few milliseconds depending on the current). There is an analog output of the picoammeter which may be connected to a faster GPIB meter if the three Hz data collection rate is too slow.

The only interface to the K485 is through the Generic Logging program.

4. Critical Opalescence Experiment Program

In the critical opalescence experiment you need to record the ratio of the laser beam's initial intensity to transmitted intensity as well as the temperature of the bath. The temperature of the bath is measured by a thermistor whose resistance is related to temperature by the formula:
\begin{displaymath}1 / T = A_0 + A_1 \ln(R) + A_2 \cdot (\ln(R))^3\end{displaymath} (1)
Both of these elements (temperature and ratio) are measured by HP 34401A multimeters, one in resistance measurement mode and one in Volts DC Ratio mode.

On the desktop of the critical opalescence machine there is a folder called LocalApps. Inside that folder you should find a shortcut named Data Collection for Critical Opalescence Experiment. Double clicking that shortcut will open up a LabVIEW program which will manage data collection from the two HP 34401A multimeters. If you want to modify the program please make a copy of all the relevant VIs (Virtual Instruments) in your own directory.

Start the VI running by clicking the arrow in the toolbar. Then click on the Configure button for the first HP multimeter. This will bring up a dialog box to configure the meter you wish to use to read the resistance of the thermistor. Configure the device appropriately (make sure to set the GPIB Address correctly). Then click the Done button at the bottom of the configuration screen to send the meter the proper configuration commands. If the meter beeps then something went wrong (this appears to happen on occasion, and if it does just reclick the configure button and click done again to resend the configuration string). The readings from this meter will be plugged into the formula given earlier before being written to the log file to give temperature in degrees C. The raw resistances will also be written to the file. After the configuration has been completed read §6 on how to operate the rest of the program. Any further changes to the configuration may only be done by stopping and restarting the logging program. After you are satisfied with the configuration of your meter you may save the configuration to a file so you can reload it quickly later by clicking on the Save Config button in the configuration dialog.

Make sure to write down the settings you chose for the meter so that you know the resolution of the numbers written to the logfile (as they are written with a fixed maximum precision) or use the Save/Load Config feature to keep track of it, but write down what file you saved the config to.

5. Ferroelectric Experiment Program

Monitoring the temperature of the bath around the ferroelectric crystal is done via watching the resistance of a temperature probe in the bath and the conversion from resistance to temperature is given by equation (1). The resistance measurement is done by a Keithley 193 System DMM. In the LocalApps Folder on the desktop you should find an application called Ferroelectric Temperature Logger. Double clicking that should start up the program to log the temperature of the bath to a file. Click the arrow in the toolbar to start the VI running. Then choose the ``Configure'' button for the K193. The GPIB address of the meter should be 30 (to change this see the manual). Use of the filtering feature of the K193 is suggested (the details of the filtering are described, once again, in the manual). When done with the settings click the Done button to close the configuration screen. Any further changes to the configuration may only be done by stopping and restarting the logging program. The meter should click and start displaying Kohms. After you are satisfied with the configuration of your meter you may save the configuration to a file so you can reload it quickly later by clicking on the Save Config button. See §6 on how to operate the rest of the logging program. There is a formula section on the front panel where you may specify the conversion formula from temperature to resistance. If you do change it you may want to right click the box and select ``Data Operations'', ``Set current value to default'' to avoid having to retype your changes later.

There is also a program tailored for doing recording from two HP 34401A multimeters (which you may decide to use for looking at hysteresis curves). The interface to this program is basically the same as that for the temperature logger and indeed both programs can be run simultaneously.

Make sure to write down the settings you chose for the meters so that you know the resolution of the numbers written to the logfile (as they are written with a fixed maximum precision) or use the Save/Load Config functionality.

  
6. Logging

After finishing configuring the devices as described in the previous sections you have to setup the remainder of the logging procedure.

In the ``Logfile Path'' type the name of the logfile you wish to write to. You should make a directory c:\user\yourname\ to store any important data, so the logfile for a given run might be c:\user\yourname\mmddyy.txt. If this is an old logfile that you want to append the data to (for example you stopped the data collection a few minutes ago and want to continue again) then make sure the ``overwrite logfile'' setting is false before continuing. If overwrite is false, the new data uses the same time base as the old logfile, that is the first column, time in seconds since logging started, is correctly calculated with respect to the initial logfile starting time.

Set the delay between readings to an appropriate number (for example 10 seconds) so you do not log more data than you can handle in an analysis program. The number in the delay setting is in milliseconds.

Click the large ``Collect Data'' button and if all is working well then the Run Indicator should turn from Red to Green. If it does not then look at the error indicator box and try to determine what went wrong. Worse comes to worse close the data logging window then restart it and try again (don't forget to click the Configure buttons before running).

If you want to pause data taking click the Pause button. If you want to stop data taking press the Stop button (this may take a few seconds to have an effect depending on what the delay between readings is).

Now the meters are reading every so often and the readings are being written to the log file you specified with a timestamp which says when the readings were taken. The format of the logfile is described in the next section. You may check that the logfile is being created by opening the logfile in notepad or some other file viewer.

Remember to CONFIGURE the device before you start logging.

7. Logfile Format

The format of the logfile is that the first line is a header:
mm/dd/yy hh:mm:ss AM/PM [floating point number encoding time]
and the remaining lines are of the form:
hh:mm:ss AM/PM [tab] [time in seconds since logfile started] [tab] dataset1 [tab] dataset2...[return]
hh:mm:ss AM/PM [tab] [time in seconds since logfile started] [tab] dataset1 [tab] dataset2...[return]
...
While the timestamps are precise to one millisecond, the actual reading time of the meter is generally pretty slow so the two readings will not be exactly synchronized, nor will the timestamp truly reflect the time of reading, instead it reflects the time when the request was sent to the meter to perform a measurement. For the critical opalescence experiment the first dataset is the resistance, dataset2 is temperature and the third is the ratio. The ferroelectric has the first dataset being resistance and the second temperature.

8. Watching the data

After the run indicator on the data logging program has turned green you should check and verify that the data is really being collected and perhaps you want to look at it a bit. So you can minimize the data collection window (it will continue to take data regardless). Now you have a choice of methods for viewing the data. You could ftp the data file to some other machine and view it with Origin or your favorite plotting package. If you look at the logfile with a program like explorer it will show it as having a length of zero, this isn't really true. FTPing your data is annoying and does not let you see what is going on now. Instead you may want to use the ``Real Time Log File Plotter'' located in the LocalApps folder.

After opening this program you will want to set the path for the logfile to what you are writing to in the logging program and click the run arrow in the toolbar.

The indicator ``Data Began'' should tell you when the logfile was first written to. The selections for datasets are now sized to the number of data columns in the file (4 for critical opalescence has time, resistance, temperature, ratio; 3 for ferroelectric time, resistance, and temperature).

This program provides two different graph types to watch your data with. The first is a ``Dual Strip Chart'' which displays two data sets as a function of time. For the critical opalescence experiment it might be useful to look at both the ratio and the temperature at the same time, so in the ``Dual Strip Chart'' area of the program set the First Plot to Dataset #2 and the Second Plot to Dataset #3 and click the Create button. This should pop-up a new window with an empty graph in it. You have to go back to the initial window and click the green ``Read Data'' button to begin sending data to the graph. You should now see the data as it is being collected. See the dual strip chart user interface section for more information on playing with the graph. If there is a tremendous amount of data in the logfile you might click ``Read Data'' before you create the graph so as to catch up to the end of the logfile. If you want to skip a large section of the file (if for example you are appending to a large data file and want to look at only the end) then modify the percent skip option before starting the VI.

The second type of plot is an ``XY Plotter''. This can be used to display either a real XY plot (one dataset vs. another) or just a single plot strip-chart (dataset vs. time). To watch the temperature as a function of time for the ferroelectric or critical opalescence experiment set x-axis to time and y-axis to dataset #2 and click the Create button and the Read Data button (if you have not already). For the critical opalescence experiment it might be nice to watch the ratio as a function of temperature, in this case set the x-axis to dataset #2 (temperature) and the y-axis to dataset #3 (ratio). See the later section on the user interface for the XY plotter to determine how to change the x-axis labels from time to a real decimal number (for displaying a real XY plot).

You may create up to five of each type of graph of the logfile by repeating the procedure above (you only need to click Read Data once either before or after you create the graphs).

There is also a program to review an old logfile that does not update in realtime, the ``Log File Review''. In the window that pops up, change the Path for logfile to be the logfile you are writing to with the data logging program and then select the run arrow in the toolbar. This program does not update in real-time and instead are geared toward reviewing a logfile that perhaps you left running over the weekend, or last night. It makes review plots much faster than loading the data through the ``Real Time Log File Plotter''.

9. Writing notes on logfiles

As most people don't tend to write things down while taking data from a computer there is a program to assist in this endeavor. Try the ``Log Timestamped Notes'' application. Make sure that you set the notes filename to something DIFFERENT from the logfile you are writing the data to, for example mmddyynotes.txt. You may type a note in the note box and click the write note to file button in which case the file will contain the date/time the note was written and the note itself. For example type ``Turned temperature knob one quarter turn'' and then write the note to the file. So when you are looking over the data in the other window you can browse through this file and see what you did at some time.

10. Plot Features

10.1 Controlling visual features

The control of the visual features of the plot is done through the gray palette below the graph. On the left-most part of the control are two tabs which select whether auto-scaling is active for the x and y axes. Placing the tabs to the left means off and to the right means on. To auto-scale the plot once, just left click the buttons right next to the tabs. To change the properties of the axes (precision, numbers instead of time, format) right click on the buttons next to the tabs.

To zoom in on a region turn off the auto-scaling features of the plots, and then select the magnifying glass and select a region. Holding the left button on the magnifying glass allows a selection of zoom types (zoom in y-axis only, zoom in area, etc.).

When using the dual-xy plotter this interface becomes a bit more complicated as there are really two plots stacked one on top of the other with a common x-axis. Using the toggle for showing one graph or both graphs in conjunction with the palette controls allows for control of both plots.

To change the x-axis from a time display to a decimal display (if you are viewing a real XY plot), press the right mouse button over the button right next to the x-axis auto-scaling tab and select the formatting menu.

It is recommended that you experiment with the logging programs and visualization tools to find the features available.

10.2 Mean and Deviation

The plots also provide a readout giving the mean and the standard deviation of the region that is currently being shown. If you are using an XY plot and have selected multiple plots to be displayed then you can use the index next to the mean and deviation display to select which plot you wish to see the numbers for.

11. Generic Logging Program

There is also a generic logging program which provides for logging from an arbitrary number of instruments (as long as it is less than five) and currently supports the following instruments: (if you wish to use the Keithley or Computer Boards DAS08 A/D cards then you want to use the LabVIEW program Acquire which is more tuned for high speed data collection).

There should be a link to the program in the LocalApps directory called Generic Logging Program. The interface is the same as for the previous programs except in this case one is able to choose the device to Configure. Use the first few device slots and leave the rest as None. Make sure to click the checkbox under ``Log Raw'' for the devices you want to write to a logfile.

12. Comments, questions

Patches to this document to ajb6@physics.umd.edu.

About this document ...

Computer based instrument control and data collection in Grad Lab

 This document was generated using the LaTeX2HTML translator Version 98.1 release (February 19th, 1998)

Copyright © 1993, 1994, 1995, 1996, 1997, Nikos Drakos, Computer Based Learning Unit, University of Leeds.

The command line arguments were:
latex2html -no_navigation -split 0 -link 6 -show_section_numbers users.tex.

The translation was initiated by Andrew Berkley on 1999-08-23

Andrew Berkley

1999-08-23

Last Edited 9/28/99 by R. Gammon
 
 
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