turbolinux.com (product: enfusion)

Indraneel Majumdar indraneel at www.cdfd.org.in
Fri Aug 11 00:18:56 PDT 2000

I have some more queries which I have inserted in between the text.
(Please remember that I seem to have less maths background than you are
assuming, but I'm trying to understand) Thanks for your replies.

On Thu, 10 Aug 2000, David Lombard wrote:
> EnFuzion is a "design scan" program.  That is, it runs tens, hundreds,
> thousands, &etc of jobs to exhaustively search a design space.  No
> modifications are required to the program being run, as it's run under
> control of a script.

What exactly is a design scan? Is it the entire range of possible input
and output values for an algorithm?

> But don't fool yourself into thinking you now have a "parallel" program
> -- you don't.
> What you do have is a tool for trying many combinations of input
> parameters as quickly as your resources will allow.  You could run these
> cases by hand (ouch) or with some scripts that use rsh(1) and rcp(1).
> The typical lowest level process for a design scan is:
> Specify the design variables and their ranges.

How do I specify the variables and ranges without knowing the algorithm? 
Generally I'll have only one set of inputs. Do I have to run the program
previously with different sets of inputs so that it can learn (similiar to
neural networks) the possible algorithm (or derive a simplified relation
between input and output)?

> Create a script that takes as input one value for each design variable,
> runs the program, and extracts whatever results are appropriate.

How does it know what results are appropriate? The program then also needs
an error checking routine (reminds me of genetic algorithms).

> Run the script with every combination of design variables and save the
> output in some form for post-processing.  The parallel processing comes
> from running the combinations on different systems.  As stated in an
> earlier post, this is the most embarrassingly parallel processing you
> can do as each run is completely independent from every other run.
> Tools like EnFuzion, iSIGHT, and others (including my own company's)
> offer varying levels of sophistication beyond this. Running the
> combinations is the easy part; achieving the desired result *without*
> running all the combinations, is the hard part.
> So, if you have a long-running program that you need to run faster, this
> is not the right approach.  If, on the other hand, you have a situation
> that is suitable to a design scan, then the method, if not the products,
> can help.
> -- 
> David N. Lombard
> MSC.Software


# Indraneel Majumdar                  ¡  E-mail: indraneel at 123india.com  #
# Bioinformatics Unit (EMBNET node),  ¡  URL: http://scorpius.iwarp.com  #
# Centre for DNA Fingerprinting and Diagnostics,                         #
# Hyderabad, India - 500076                                              #

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