Subject: Announcing PICT2.1 - Now fully Operational

From: Roger Hockney <[email-masked]>
Date: Wed, 22 Apr 1998 11:59:51 +0100

To: the Parkbench discussion group

From: Roger

                   ANNOUNCING PICT 2.1 (1 Mar 1998)
                   --------------------------------

I am pleased to announce the first fully-functional version of the 
Parkbench Interactive Curve-Fitting Tool (PICT).

Provision is made for a wide range of screen sizes in pixels by
allowing the user to make a suitable choice in the opening HTML page.

All buttons now work. In particular Jack can have his least-squares 
fitting of the 2-parameters direct from the tool, and this can be 
performed over partial ranges of the data as required. The same 
applies to the Three-point fitting procedure to obtain the 
3-parameter fits.

There is also a nice "Temperature Gauge" feature that helps you 
minimise the error during manual fitting.

The results of these fits can be assembled in a results file and 
annotated using the SAVE buttons. Under MSIE I find I am able to 
store these results in my local disk file system using SAVE as ...

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The methodology of the 2-parameter curve fitting is given in detail 
in my book "The Science of Computer Benchmarking", see: 

              http://www.siam.org/catalog/mcc07/hockney.htm 

The 3-parameter fit was described quite fully in my talk to the 
11 Sep 1997 Parkbench meeting. I have finally written this up with 
pretty pictures for the PEMCS Web Journal. Look at:

    http://hpc-journals.ecs.soton.ac.uk/Workshops/PEMCS/fall-97/
           talks/Roger-Hockney/perfprof1.html

To try out PICT 2.1 please first try my own Demon Web space which 
has a counter from which I can judge usage: 

       http://www.minnow.demon.co.uk/pict/source/pict2a.html

If this gives problems, it is also mounted on the University of 
Westminster server:

   http://perun.hscs.wmin.ac.uk/LocalInfo/pict/source/pict2a.html

We expect soon to make it available on the Southampton server.

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PICT 2.1 has been tested by a small number of friends. Most 
problems and frustrations arise from either slowness of the 
server or of the users' computer.

If download from Demon is slow or appears to hang, try the other
server or try Demon later. Please do not conclude the applet is 
broken. I am confident it is not. A 10 to 20 second wait is 
normal when bringing up the requested graphical window/frame 
even on a good day.

Once the graphical window is on your computer and the applet is 
running, the speed is determined by the speed of your computer.

You may even disconnect from the Web at this stage and continue 
curve fitting with the applet with the data displayed. If you 
want new data, you must, of course, reconnect to the Web and 
use the GET DATA at URL button.

Experience shows that the PICT applet will not respond 
satisfactorily on a computer with slower than a 100 MHz clock. 
This is because a lot of complex calculations must be performed 
as you drag the curves around the data. MSIE seems to work
noticeably faster than Netscape on my Win95 PC. There is no
cure for this except to use a faster computer. But again
please do not think the applet is brocken.

Please report experiences good or bad to:

              [email-masked]

Constructive suggestions for improvement are also welcome. 
-- 
Roger Hockney.  Checkout my new Web page at URL   http://www.minnow.demon.co.uk