Subject: NA-NET distribution message

From: [email-masked]
Date: Sun, 25 Jun 89 12:52:00 PDT

NA Digest   Sunday, June 25, 1989   Volume 89 : Issue 25

Today's Editor: Cleve Moler

Today's Topics:

     Professorship in Trondheim
     Freund Wins Award
     Mininization Problem
     Positions at Bergen Scientific Centre
     Vector/Parallel Polynomial Arithmetic
     Scientific programming in C++
     No NA News Digest Next Week

-------------------------------------------------------

From: Hans Munthe-Kaas <[email-masked]>
Date: 19 Jun 89 10:19 +0200
Subject: Professorship in Trondheim

           The Norwegian Institute of Technology
           Division of Mathematical Sciences

           Full Professor of Mathematics (Numerical Analysis) 

The Norwegian Institute of Technology invites applications for a tenured 
position as Full Professor of Mathematics (Numerical Analysis). The Division of
Mathematical Sciences is part of the Department of Physics and Mathematics, 
and currently has 23 faculty positions, 11 of which are full professorships. 
The Division offers a program in Industrial Mathematics leading to the 
engineering degree of siv.ing. (at M.S. level), and has a doctoral program 
leading to the dr.ing. degree. The program in Industrial Mathematics consists 
of courses in mathematics, numerical analysis and statistics, with a general 
emphasis on mathematical modelling. Research interests of the current faculty 
in numerical analysis include numerical quadrature, spline approximations, 
numerical solution of ordinary differential equations and numerical linear 
algebra.

Special emphasis will be placed on qualifications of candidates in areas of 
numerical analysis with relevance to numerical modelling using vector or 
prallel computing algorithms; in particular qualifications within numerical 
linear algebra, numerical solution of differential equations, and numerical 
optimization.

Applicants are sought who show significant research accomplishments as well as
serious concern for teaching, and commitment to initiating and promoting 
research.

The closing date for receipts of applications is September 1, 1989.

The Professor is engaged on the condition that he/she at 
any time participates in teaching and examination work in accordance with the 
relevant program of study, and furthermore he/she must accept, without 
compensation, any revisions made by statutory law or royal decree to curricula,
pension arrangements and retirement age.

A letter of application including a curriculum vitae and a list of 
publications should be addressed to The King and sent to:
     
     The University of Trondheim
     The Norwegian Institute of Technology
     Personell Section
     N-7034 Trondheim
     Norway.

In addition, reprints and preprints should be sent, in quadruplicate, to the 
same address, no later than one month after the closing date. Work in progress,
referred to in the letter of application, must arrive within three months 
after the closing date.

Further information is available from the above address.

------------------------------

From: Rich Sincovec <[email-masked]>
Date: Wed, 21 Jun 89 17:48:10 -0700
Subject: Freund Wins Award

Roland Freund was recently informed that he is the recipient of the
"Heinz- Meier-Leibniz Award".  It is awarded by the German Secretary
of Education and Science.  It is a one time award related to the
anniversary of some important event in science (possibly Leibniz's
birthday).  It is awarded in three different fields: Public Law,
Applied Math, and some engineering discipline.  The award honors 
important contributions of junior scientists not older than 33 years.
Roland will receive the Applied Math Award which also includes a
monetary award.  Roland did not know that he was nominated for this
award until he received notice that he was the recipient of the award.
A committee selected Roland based on the quality and the importance of
his research papers.

Roland will receive the award this week in a ceremony held in an old
castle which is part of the University in Muenster.

Congratulations, Roland!

------------------------------

From: AlBert DeKnuydt <[email-masked]>
Date: Thu, 22 Jun 89 18:11:27 GMT
Subject: Mininization Problem

This MAIL contains a description of a problem on numerical
minimisation and numerical differentiation.  The domain of
the problem is image processing.

1) Function description :

The rather complicated function to minimize depends on 5 
variables.  These 5 variables define an image of which a
histogram is calculated. The function result is the following
operation on this histogram. (In fact the entropy)

N(i)   =   number of occurrences of value i
N      =   total number of occurrences

function_result =  -  SUM    [N(i)/N] * blog [(N(i)/N)]
                   all i with 
                   N(i) <>  0 

One single function evaluation takes about 3 minutes CPU on a
VAX 8530.

2) What we tried up to now :

We tried the following NAG routines.

E04JAF  :  Quasi Newton algorithm using function values only, 
           easy-to-use version.

           Problem : accurracy of result nor function 
           evaluation not controllable.  Routine doesn't use
           large enough steps towards the minimum.
           
E04JBF  :  Quasi Newton algorithm using function values only, 
           comprehensive (= not "easy-to-use" ?) version.

           Problem : steps too small.  Routine E04HBF, used
           to determine initial step length for making 
           difference approximations to the partial
           derivatives of the target function, expects target 
           function to be of machine accuracy. Because our
           function is essentially discrete, this is
           questionable.

E04VCF  :  Sequential QP (Quadratic Programming) method,
           using first derivatives.

           Problem is now with the routine to calculate these
           derivatives.  It almost always returns with  a
           diagnostic complaining about accuracy (forward and
           central difference estimates don't agree to half a
           decimal place).  When we check these derivatives
           with E04ZCF, it says it doubts about the
           correctness of the derivatives.  Probably, the
           cause is the slightly discrete character of  the
           target function.

(We use MARK 12 release of the NAG library, if this is of any
 importance)

3)Questions 

Anybody has an idea :
    
           What the reason of the failure of the NAG routines
           might be ? And how to solve this ? 

           Of another way to minimize this kind of function ?

eMAIL [email-masked]           UUCP
      deknuydt%kulesat.uucp@blekul60  BITNET

B. DeKnuydt & J. Smolders
K.U.Leuven ESAT/MI2 
Kardinaal Mercierlaan 94
B-3030 Heverlee-Leuven
B E L G I U M

------------------------------

From: Pat Gaffney <[email-masked]>
Date: Fri, 23 Jun 89 16:02:31 EMT
Subject: Positions at Bergen Scientific Centre

           BERGEN SCIENTIFIC CENTRE - JOB OPPORTUNITIES

           Reservoir Modelling-Numerical Algorithms-Software Development

Bergen Scientific Centre, IBM, is building up its research activity based on
numerical oil reservoir modelling. This work involves the development of
adaptive multigrid solvers for Navier Stokes flows and the development of
multigrid solvers for reservoir simulation. Current areas of interest
include : automatic error estimation and grid refinement, parallelization on
shared/distributed memory architectures and the treatment of complex
geometries. The orientation of this work is with a view to using
parallel/vector computer architectures.

We are looking for scientist(s) interested in either of the following
areas:

         APPLIED MULTIGRID/DOMAIN DECOMPOSITION METHODS

            STOCHASTIC PARTIAL DIFFERENTIAL EQUATIONS

as related to oil reservoir simulation.

Appointments in these areas will be for a period of one or two years.

Bergen provides a pleasant environment in the heart of the Western
Fjords of Norway with excellent opportunities for outdoor pursuits
especially skiing, and water-sports. The centre is English speaking
and provides a friendly and flexible environment for scientists of
many different backgrounds.

Contact Chris Thompson at either of the electronic mail addresses:

                   THOMPSON AT KRYPTON.BSC.NO
                    FSCCT AT NOBERGEN.BITNET
or

Aladin Kamel:
                    ALADIN AT KRYPTON.BSC.NO
                    FSCAK AT NOBERGEN.BITNET
or

Patrick Gaffney:
                      PAT AT KRYPTON.BSC.NO
                    FSCPG AT NOBERGEN.BITNET

------------------------------

From: John R. Rice <[email-masked]>
Date: Fri, 23 Jun 89 12:31:24 EST
Subject: Vector/Parallel Polynomial Arithmetic

           Vector/Parallel Polynomial Arithmetic 

   Does anyone know of software or algorithm implementations of
polynomial arithmetic for vector or parallel machines?  We are
interested in
 
        Univariate & Sparse Multivariate Polynomials

and the operations:

      Multiplication			Division
      Evaluation at multiple points	Interpolation
      Residue computation

Reply to   John R. Rice   jrr&cs.purdue.edu   317-494-6003
           C. Bajaj       [email-masked] 317-494-6531

------------------------------

From: Jon Claerbout <[email-masked]>
Date: 25 Jun 89 02:01:53 GMT
Subject: Scientific programming in C++

Scientific programming in C++ ?

ABSTRACT:
I converted some simple scientific Fortran/Ratfor programs into C++
to see if they would look suitable for a textbook
such as my last book "Imaging the Earth's Interior".
I conclude C++ is about as good as fortran-ratfor.
Unfortunately, mixing Fortran with C++
ranges from undocumented to impossible.

BOOK REPORT
The new Lippman C++ book looks like a replacement for the Stroustrup book
since it fully describes the new AT&T version 2.0.
Pedagogically it is a big improvement too.
Since both Stroustrup and Lippman describe both C and C++
I infer they mean eventually to replace C by C++
(else why the 100+ extra pages to explain C
which K&R already do beautifully)?
A section called "linkage to other languages" mentions C but not Fortran.

PROGRAMS
We couldn't link gnu C++ mains to fortran subroutines.
I converted some simple fortran scientific programs to a C++ style
designed to please fortran users
and I posted them to [the UNIX network newsgroup] comp.lang.fortran.

   Jon Claerbout
   Dept. of Geophysics
   Stanford University

------------------------------

From: Cleve Moler <[email-masked]>
Date: Sun Jun 25 12:43:27 PDT 1989
Subject: No NA News Digest Next Week

I'll be out of town next weekend, and things are pretty slow
anyway, so it will be two weeks until the next NA News Digest.
Happy Fourth of July.
  --Cleve

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