CATAM News 1999-2000
What's new in C A T A M
Read CATAM News for up-to-date information about the Computational Projects and changes to the PWF network facilities.
Recent CATAM news headlines:
01 May 00 Accessing the PWF over the Bank Holiday 30 Apr 00 Location for submission of projects 26 Apr 00 Electronic submission of project files 25 Apr 00 Helpline deadline 25 Apr 00 Ring binders now available from DAMTP 21 Apr 00 Very Minor Correction to Part II project 5.3 18 Apr 00 Easter Closing Arrangements 12 Apr 00 Correction to Part II project 8.5 31 Mar 00 Correction to 1B project 2.5 23 Mar 00 Printer credit on the CATAM printers. 23 Mar 00 CATAM on PWF computers running Windows NT (update) 22 Mar 00 Usage of Maple in project 14.3 10 Mar 00 Correction to part II project 15.6 17 Feb 00 Ring binders availability 15 Feb 00 Part II: Minor correction to project 3.5 4 Feb 00 CATAM Room PCs reserved Tue/Wed a.m. 28 Jan 00 Warning on collaboration 1 Jan 00 New CATAM Director 31 Dec 99 Part II: Minor correction to project 3.5 31 Dec 99 Part II: Correction to project 20.3 9 Dec 99 Part II: Clarification in project 16.5 1 Dec 99 C CATSL library and compiler available for download 29 Nov 99 Christmas Closing Arrangements 5 Nov 99 CCATSL C1.0 available on Maths PWF 26 Oct 99 CATSL version 2.4.2 on Maths PWF 4 Oct 99 Welcome back & Demonstrator availability 4 Oct 99 New edition of the CATSL manual 28 Sep 99 Part II: Correction to project 15.7 1 Sep 99 Part IB: Correction and hint for project 2.6 1 Sep 99 Part IB: Correction to project 1.2 1 Sep 99 Part II: Clarification for project 3.5 1 Jul 99 - Colour printer now available in the CATAM Room 1 Jul 99 - Keep your project files secure. 1 Jul 99 - Mill Lane Lecture Rooms security 1 Jul 99 - Hard disk cleanup on PCs and Macs
News Headlines 1998/99 News Headlines 1997/98 News Headlines 1996/97
01 May 00 - Accessing the PWF over the Bank Holiday
Some IB students may have difficulty accessing their PWF account over the bank holiday. If so, they may submit electronically on Tuesday, PROVIDED their write-up is submitted on Monday and they explain this when submitting their write-up.
Dr Y. Git
CATAM Director
30 Apr 00 - Location of submission of projects
Project write-ups should be submitted in room s26 which is on the second floor of the old statistical laboratory in Mill Lane.
Dr Y. Git
CATAM Director
26 Apr 00 - Electronic submission of project files
Click here for instructions on how to submit CATAM project files electronically.
25 Apr 00 - Helpline Deadline
The CATAM Helpline is currently still answering queries, but will be unable to answer any new queries sent to the Helpline after Wednesday 26th April except on straightforward matters concerning submission etc.
Dr Y. Git
CATAM Director
25 Apr 00 - Ring Binders now Available from DAMTP
The project ring binders are available for collection from the DAMTP Reception.
Dr Y. Git
CATAM Director
21 Apr 00 - Very Minor Correction to Part II project 5.3
On page 2 of this project, in the equations for the eigenvector components e_n, the condition n>1 should of course read n>0. This correction should not make any difference to you, but is issued for completeness.
Dr Y. Git
CATAM Director
18 Apr 00 - Easter Closing Arrangements
The Mill Lane Lecture Rooms building will be closed (and the computer room will hence not be available) from Friday 21st April till Monday 25th April inclusive.
Dr Y. Git
CATAM Director
12 Apr 00 - Correction to Part II project 8.5
Near the end of page 2 of this project it is stated that aR < min r(i). This should read aR <= min r(i). This minor error does not affect the rest of the project.
Dr Y. Git
CATAM Director
31 Mar 00 - Correction to 1B project 2.5
In the closing question (iii)c, the formula for T should be corrected so that:
T=2 log f(OQ_i|beta-hat_1,beta-hat_2, beta-hat_3,mu-hat,sigma-hat^2)-2log....
Dr Y. Git
CATAM Director
23 Mar 00 - Printer credit on the CATAM printers.
If you run out of credit on the PWF-MATHS printers send email to the CATAM helpline. Do not go to Computing Service Reception - they do not sell printer credit for the CATAM printers.
Before an additional printer credit is allocated you may be asked to explain why the 300-page allocation for your Project work was not sufficient.
David Harris
Computer Officer
CATAM Support
DAMTP
23 Mar 00 - CATAM on PWF computers running Windows NT (update)
To access the CATAM software and Borland Pascal on University PWF PCs running Windows NT:
- Click on the Start button in the lower-left corner of the screen.
- Select PWF Programs and information.
- Select Teaching Packages.
- Select CATAM.
- Click on Borland Pascal for CATAM.
Note: do not start Borland Pascal from the Start/Programming Languages/Borland Pascal menu item as this does not access the CATSL library units, and you will see a compilation error message about CTbase not being found.
Warning. You should not start your program executing using the Pascal Run menu. Instead use the Windows Start button as described below. Borland Pascal is "16-bit" software originally written to run on Windows 3.1. The compiler produces 16-bit executable programs (.EXE files) which work perfectly well with modern "32-bit" versions of Windows (95, 98, NT) provided the programs are not started from within the Pascal editor.
To run a Pascal program on a Windows NT system:
- Compile the .PAS file using the Compile menu, or press function key F9.
- Click on the Windows Start button in the lower left-hand corner of the screen.
- Click on Run...
- Type the name of the executable program file, for example:
F:\projects\XXXXX.EXE
where XXXXX is the name of your Pascal program file minus the .PAS.
(The Pascal compiler is configured to build executable files in the F:\projects folder on the PWF).
You need to type the name of the executable file only once - Windows keeps the names of previously started files in a drop-down list - click on the small black triangle (an inverted delta) to display the list and then choose the program you wish to start.
Note: the CATAM software is also available on the on the Computing Service PWF networks in the Phoenix User Area, Phoenix Teaching Classroom and Old Music School.
If you do encounter any problems using Windows NT, please send email to the CATAM helpline.
David Harris
Computer Officer
CATAM Support
DAMTP
22 Mar 00 Usage of Maple in project 14.3
There has been a confusion regarding what Maple routines can be used in this project. The project was intended (and should be attempted) using only routines which are available in the student version of Maple. An online short tutorial is available [.ps, .pdf].
As the original phrasing of the project was less than clear, no marks will be dedcuted if routines from the full version of Maple are used, as long as the routines do not relate directly to tensor manipulations.
Dr Y. Git
CATAM Director
10 Mar 00 Correction to part II project 15.6
Question 8 should read: Discuss the extensions of these two methods to the computation of q-th roots mod p for q>3. When q is prime, distinguish the case p=1 and p=/=1 (mod q).
Dr Y. Git
CATAM Director
17 Feb 00 Ring binders availability
As the DPMMS reception in Mill Lane is no longer operating, project ring binders are available for collection from the Statistical Laboratory reception (access through the back door of DPMMS, and is on the first floor) until April.
Dr Y. Git
CATAM Director
15 Feb 00 Part II: Minor correction to project 3.5
Just before Q3, the sentence should read: "You may find it useful to plot P(R,r) against r normalised so that..." instead of "P(R,r) against R..."
Dr Y. Git
CATAM Director
4 Feb 00 CATAM Room PCs reserved Tue/Wed a.m.
Please note that the CATAM Room PCs are reserved for Part IIA Statistics practicals for the remainder of this term:
Tuesday mornings 9am to 10am and Wednesday afternoons 12 noon to 1pm
28 Jan 00 Warning on collaboration
There has been an incident this term of a 1B student who tried to obtain answers for the CATAM projects by posting questions on various newsgroups on the net. It should be stressed that asking someone to answer part of your project or to write for you some of your program is not allowed and the medium by which answers are sought is irrelevant (e.g fax / phone / letter / posting on newsgroups etc).
You are allowed to use the CATAM software library / standard textbooks on numerical algorithms (if credited in project) for programming. You are allowed to ask demonstrators / CATAM helpline questions related to the Maths, and some limited discussions with fellow students is also allowed (indeed, encouraged). You can also obtain some feedback from supervisors / director of studies.
Otherwise, if you would be uncomfortable to ask a compsci friend to write you a program or uneasy to ask CATAM helpline a maths question, then it is a good sign that you should not post a newsgroup question on this question / algorithm!
Dr Y. Git
CATAM Director
1 Jan 00 New CATAM Director
As of today, Dr Yoav Git of the Statistical Laboratory is the Director of CATAM. Dr Robert Hunt will still be heavily involved with CATAM as the Chairman of the Computational Project Assessors Committee. Queries about CATAM should continue to be addressed to the CATAM Helpline.
Dr R. E. Hunt
Chairman of CPAC
31 Dec 99 Part II: Minor correction to project 3.5
(Collapse of a Spherical Cavitation Bubble)
In the second bulleted paragraph of Question 3, the first sentence should read "Equation (7) is non-analytic at x=0." The second sentence is correct as it stands. The online copy of the project has been corrected.
Dr R. E. Hunt
CATAM Director
31 Dec 99 Part II: Correction to project 20.3
(Last man standing: Markov chains in two dimensions)
In part (c)(v), it is not required that you find a closed-form formula for f(n,n) in the cases a = -1, 1, 2. The online copy of the project has been altered to make this clear.
Dr R. E. Hunt
CATAM Director
9 Dec 99 Part II: Clarification in project 16.5
(Permutation Groups)
In section 3, second paragraph, the reference to the "(1,pi_l)th entry in the first row" (where _ denotes a subscript) means the entry in the first row and in column number 1pi_l. Note that in the notation of this project, 1pi_l means the element of the set X = {1, ..., n} obtained by applying pi_l to the element 1.
Similarly in the third paragraph.
Dr R. E. Hunt
CATAM Director
1 Dec 99 C CATSL library and compiler available for download
The C version of the CATAM software library for Windows 95/98/NT is available for download from http://www.maths.cam.ac.uk/catam/ccatsl.
29 Nov 99 - Christmas Closing Arrangements
The Mill Lane Lecture Rooms building will be closed over the Christmas period from Thursday 23rd December to Monday 3rd January inclusive. Note also that the Mill Lane Lecture Rooms building is closed on Saturdays outside Full Term.
When the building is closed, the PWF will be available for use by MLLR keyholders, but a continuous service cannot be guaranteed during the Christmas holiday period.
CATAM demonstrators will be available at the usual times during the week following the end of Michaelmas Full Term and the week preceding the start of Lent Full Term.
5 Nov 99 CCATSL C1.0 available on Maths PWF
CATAM Software Library - CCATSL - Version C1.0
This is the first release for testing of the C version of the CATAM software library. The package consists of the gcc compiler, the emacs editor, and the CATSL function library, together with other useful tools such as gnuplot and (soon) TeX/LaTeX translators.
C is scheduled to be the main supported programming language for Mathematics Computational Projects from October 2000. This initial release is being made available for use by experienced C programmers - there is as yet no C-specific CATSL documentation, and the demonstrators may not be able to answer questions about the C implementation of the library. Updates and improvements will be introduced over the coming year, and we welcome suggestions and comments by email to catam@maths as input to this process.
The Pascal version of CATSL will be supported until at least summer 2001 for Part II students who programmed in Pascal in Part IB, and thereafter while there is demand for support from students using the Pascal software on computers at home. However, the C version will be freely available for use on college and home computers, and we will strongly recommend that it is used instead of Pascal from next October.
If you are not an experienced programmer you are most strongly advised NOT to use C this year.
CCATSL is available only on PWF-MATHS at present. A downloadable version will soon be available. To access the software:
- Click on the Start button in the lower-left corner of the screen.
- Select PWF Programs and information.
- Select Teaching Packages.
- Select CATAM.
- Click on C Programming Tools.
David Harris
CATAM support
DAMTP
26 Oct 99 CATSL version 2.4.2 on Maths PWF
CATSL version 2.4.2 is now installed on the Maths PWF in Mill Lane.
In earlier versions, when running under Windows NT, the standard Pascal error message was not displayed after a run-time error occurred.
For example, if an out-of-range array index is used, a CATSL program will now display a pop-up message window "Runtime error 201 at 0001:xxxx" where "xxxx" indicates the location of the error in the machine code program produced by the Pascal compiler. This location can be of use in tracking down where an obscure run-time error occurred in your program - you will need to generate a "linker map" file to assist with this (see Pascal on-line help for Map File Options), but we recommend you use the normal techniques for debugging: add extra writeln and conditional (if) statements to your program. Better still, spend time designing your program before starting to write code.
To find out what a particular error code means see the Pascal on-line help.
David Harris
Computer Officer
CATAM Support
DAMTP
4 Oct 99 Welcome back & Demonstrator availability
Welcome back to Cambridge after the summer. Good luck with your CATAM projects: we hope everything will go as smoothly as possible.
Demonstrators are available in the CATAM Room during Full Term on Mondays to Fridays between 2pm and 4pm. They will also be available during the week after the end of each of Michaelmas and Lent Full Terms, and during the week before the start of each of Lent and Easter Full Terms. Please remember that the demonstrators are available to help sort out any problems you might have with CATAM: you can ask them to help with difficult parts of your programs, to help debug your code, and for clarification of any of the projects, including mathematical aspects.
If the demonstrators are unable to solve your problem, do feel free to ask the CATAM Helpline by e-mail: catam@maths.cam.ac.uk. This is also the way to report broken machines in the CATAM Room and potential errors in the projects.
Dr R. E. Hunt
CATAM Director
4 Oct 99 New edition of the CATSL manual
A new edition of the yellow manual (The CATAM Software Library, Version 2.4) is now available from DAMTP reception for 4 pounds. There are also copies in the CATAM Room, one by each computer. The entire manual can be viewed online (follow the link to the CATSL Manual from the CATAM home page).
The new edition is very similar to the previous edition, but various corrections and updates have been made and some explanations have been improved. A new section on using arrays which are larger than Pascal's built-in limit has also been included. I regret that there is no reduction in price available to students who wish to "upgrade" their manual from the previous edition.
The green manual (Learning to use Pascal and the CATAM Software Library) is still available for 2.50.
Dr R. E. Hunt
CATAM Director
28 Sep 99 Part II: Correction to project 15.7
(Continued fractions)
The definition of "machine epsilon" is missing an important word. It is the smallest positive real number such that 1+epsilon is found to be not equal to 1.
Dr R. E. Hunt
CATAM Director
1 Sep 99 Part IB: Correction and hint for project 2.6
(Public Key Cryptography)
In question 11, you are told that you may assume that n^2 < 2^31, where ^ denotes a superscript. This should read ((n-1)/2)^2 < 2^31. The online copy of the project has been corrected.
You may like to consider the following hint when writing the program for this question. Suppose two numbers, a and b say, are given in the range 0 <= a,b < n, and that it is required to calculate their product a*b mod n. The value of the product (mod n) is unaffected if a is replaced by a-n, and similarly for b. It is therefore possible to ensure that the moduli of both a and b are within a certain range (of size smaller than n) before the multiplication is performed. The result of the multiplication may then be negative, even after the mod n operation, in which case you will need to take steps to ensure that the final result of the multiplication is positive.
Dr R. E. Hunt
CATAM Director
1 Sep 99 Part IB: Correction to project 1.2
(Matrices over Finite Fields)
Question 6 contains two minor but unfortunate errors. The right-hand side vectors in parts (b) and (c) should read (2,1,0) and (3,2,1,4,16) respectively. Apologies for this mistake.
Dr R. E. Hunt
CATAM Director
1 Sep 99 Part II: Clarification for project 3.5
(Collapse of a Spherical Cavitation Bubble)
In question 3 of this project, you are asked to solve (7) for lambda=0 in order to obtain a value for t_c; you will need to evaluate an integral to achieve this. You are not expected to do the integration analytically: you may evaluate the definite integral numerically, or otherwise. The online version of the project has been updated to reflect this clarification.
Dr R. E. Hunt
CATAM Director
1 Jul 99 - Colour printer now available in the CATAM Room
The HP Laserjet 4500 in the CATAM Room is now working under Windows 3.1 To use the printer:
- Double click the Utilities group icon - Double click the Setprint icon - Click on the line: Mill Lane (CATAM) HP Laserjet 4500 - Click on Apply to make this printer the current default printer. - Click on Exit
Pages on the monochrome Laserjet cost 4p, on the colour Laserjet, 10p.
Note: the Balance enquiry button of Setprint does not work at the moment - please use the separate Wbalance utility to check your printer balance.
All Part IB/II students have been credited with a £12.00 pounds printer balance, which should be sufficient for project work.
Please mail queries about the new printer to the catam helpline.
David Harris
Computer Officer
CATAM Support
DAMTP
1 Jul 99 - Keep your project files secure.
Do not leave copies of your project files behind on the local hard disk of PWF or College computers. If someone took a copy of your work and incorporated it in one of their own programs, you might be falsely accused of unfair collaboration by the Project Assessors.
If you lose a floppy disk containing your programs, please report it to the CATAM helpline.
David Harris
Computer Officer
CATAM Support
DAMTP
1 Jul 99 - Mill Lane Lecture Rooms security
The Mill Lane Lecture Rooms building is closed at 5pm, Monday-Friday and at 1pm on Saturday. The ground floor doors are deadlocked at closing time so please leave promptly otherwise you will be TRAPPED inside the building!
The hours for which the MLLR building is open are restricted by the University insurers. If theft or damage should occur in a building which is not properly secured the University would not receive full compensation from the insurers.
Only authorised keyholders are allowed to work in the CATAM Room at night when the MLLR building is locked. Students MUST NOT UNDER ANY CIRCUMSTANCES be in the building outside the official hours - see the Part IA/IB and Part IIA/IIB Project Booklets for details. If you do find yourself locked in the building at night telephone the University Security Centre on 31818. The PWF logon records are monitored and anyone found working without permission when the building is locked will be reported to University authorities.
Users of the Maths PWF may also use the Phoenix User Area and Old Music School PWFs which are operated by the University Computing Service. Late-access keys are available from the Computing Service Reception, Pembroke Street.
David Harris
Computer Officer
DAMTP
1 Jul 99 - Hard disk cleanup on PCs and Macs
Please note that the local hard disk drives on the Maths PWF PCs and Macs will be cleaned up regularly with little or no warning. You should not keep any permanent files on the hard drive unless you have made arrangements to do so with CATAM staff (email catam@maths.cam.ac.uk). In particular, never store your Computational Project files on the hard drive where they might be deleted or read (and copied) by others.