NA Digest Saturday, February 20, 1988 Volume 88 : Issue 8

Today's Editor: Cleve Moler

Today's Topics:


From: Mark Kent <>
Date: Fri, 19 Feb 88 20:55:11 PST
Subject: New, improved NA-NET
Status: RO

Quite a while ago I moved the na.<lastname> facility from to another machine (almost transparently).
Now we can bypass too.

Following are the new instructions for the NA-NET.

% Requests, comments or problems to
% Submissions for broadcast to
% Note: Most people will be able to mail to host "".
% However, for those who can't, the mail can be routed through another
% machine: e.g.,, or
% The only people who may have problems getting to na-net are those
% on the Arpa-Internet who are using static host tables rather than
% name resolution software. I believe that all the major gateways
% to the other nets have good software and there should be no problem
% with mailing from bitnet (netnorth, earn) or csnet sites. All
% uucp sites that enter the Arpa-Internet through a "good" host
% will also have no problems e.g.,,,
% This list is not exhaustive.

The "old" way will still work for quite a while
(i.e., and na.<lastname>,
but I think that score itself will disappear this year.

Coming features: SOON, but not YET, we will drop the "na." in
the na.<lastname> facility.

-- Mark Kent


From: (The NA-NET)
Date: Fri, 19 Feb 88 21:55:34 PST
Subject: NA-NET statistics

The digest is currently mailed out to 821 distinct addresses.
The mailing list is split over eight cpu's roughly according to
(what I perceive is) the distance from Stanford of the recipient.
Here is the current breakdown:

#addresses #connections "sample distance"

group1 90 28 trans-atlantic Internet
group2 83 40 East coast USA
group3 100 37 .gov and .com hosts
group4 107 23 Midwest USA and uunet
group5 61 39 Washington, Utah and Texas
group6 72 35 California
group7 236 1 bitnet (through Stanford gate)
group8 72 1 csnet

The number of connections is the minimum number of mail connections
that must be made by our hosts in order to get the mail off our systems.
(guess which one is my workstation.)

Here are the usage figures of the na.<lastname> facility
since we started keeping track.

6730 messages from Feb 12 to Aug 19 (1987)
3133 messages from Aug 19 to Nov 8 (1987)
1966 messages from Nov 8 to Dec 14 (1987)
1405 messages from Dec 14 to Jan 19 (1987-88)
1856 messages from Jan 19 to Feb 19 (1988)

So, in a year and a week, we have processed over 15,000 messages from
one individual to another. The na.<lastname> facility has
over 1050 entries. You can get the current list by mailing
to or with the
send nalist from misc

--Mark Kent


From: James Pool <>
Date: Sat, 13 Feb 88 10:29:52 PST
Subject: Change of Address for Jim Pool

Effective February 9, I resigned my positions as Executive Vice-President
and as a Director of The Numerical Algorithms Group (U.S.A.) Incorporated.
I plan to take a respite and then seek a new position.

During this period, please use the following temporary points of contact:

US Postal Address

James C. T. Pool
9 South 532 Drover Lane
Downers Grove, IL 60516


(312) 985-3305



From: Richard Bartels <>
Date: Sat, 13 Feb 88 15:02:05 EST
Subject: Special Issue, ACM Transactions on Graphics

ACM's Transactions on Graphics solicits papers for a special
issue on computer-aided geometric design and geometric modeling.
Topics of interest include, but are not limited to:

* parametric curves and surfaces
* algebraic curves and surfaces
* procedurally defined curves and surfaces
* solid modeling
* polynomial and spline techniques
* blending and filleting
* geometric continuity
* sculpting paradigms
* engineering applications
* interaction techniques
* curve and surface fitting

Five copies of each submitted manuscript should
be sent to the following guest editors:

Richard Bartels and Ron Goldman
Computer Science Department
University of Waterloo
Waterloo, Ontario N2L 3G1

The schedule is as follows:

Submission deadline 15 September, 1988
Notification 15 January, 1989
Revision 15 March, 1989
Publication July, 1989

For style requirements, please see the July, 1987,
issue of ACM's Transactions on Computer Graphics.
Prospective authors may discuss their plans informally
with one of the guest editors by contacting them at
(519) 888-4534 or via their electronic mail addresses or


From: Arunava Majumdar <majumdar@ucbvax.Berkeley.EDU>
Date: 18 Feb 88 00:21:12 GMT
Organization: University of California, Berkeley
Subject: PDE solver needed

I need a package to solve the following form of
a PDE:

u [n] + u [n] = f(u[n])
x y

where u is a n x 1 vector. To solve this system of
equations, 2n boundary conditions are needed. In my
problem the boundary values of u are distributed
over all the boundaries, ie, x=0, x=l, y=0, y=L.
I need to find the field of u within these boundaries.

Is there any package which solves this type of system
of PDEs? If so could someone let me know the name and
if possible how to get hold of such a package.


--- Arun


Date: Wed, 17 Feb 88 16:37:44 MST
Subject: Format bug in PARANOIA

Sorry if this duplicates earlier postings... I recently got a copy of
PARANOIA and tried running it on our CDC Cyber 840 and discovered a minor
bug. In the single-precision Fortran version there is a subroutine PARTUF
which has a FORMAT statement with a label of 4815. In this format there is
a literal character string 'zname' which needs to be changed to an A2
specification or you might end up trying to print a character string via
an E16.8 specification. I do not know about the double-precision version.
I have dropped a note to Richard Karpinski about this.

Has anybody found any other bugs?


From: Cleve Ashcraft <>
Date: 20 Feb 88 17:51:50 GMT
Organization: Yale University, New Haven, CT
Subject: Triangularization of 2-d Domains

I am interested in ordering sparse matrices arising from 2-d finite
element problems which use linear triangular elements. The density
of the grid points in the domain should be roughly equal throughout
the domain, and the triangularization should be "good". The
triangularization should exhibit no apparent regularity, this last
property is very important.

Can anyone recommend book or journal articles on this subject?
Thanks in advance.

Cleve Ashcraft
C. S. Dept
Yale University
203 -- 432 -- 1221


From: Dick Beyer <>
Date: Sat, 20 Feb 88 12:56:21 PST
Subject: Query about singular forcing functions

I am interested in numerical methods and error analysis
for PDEs with singular forcing functions. For example,
a delta function source whose location and strength depends
on the solution of the PDE.

In particular, I would like to use a uniform finite
difference grid. Since the source location will not, in
general, be at a grid point, some interpolation will be
necessary. I am interested in deriving or locating second
order accurate methods for such problems.

I have not had any success searching the literature and
wondered if anyone might point me to a possible reference or

Please address email to


Dick Beyer