Re: Scientific calculations (was Re: Ada vs Delphi? )

["Vladimir Olensky" <vladimir_olensky@yahoo.com>]

Robert Dewar wrote in message <7ovp6j$vrl$1@nnrp1.deja.com>...
>In article <rr3kb1t2krl47@corp.supernews.com>,
>  "Vladimir Olensky" <vladimir_olensky@yahoo.com> wrote:
>> Taking into account your comments I might think that you
>probably are not
>> very familiar with these tools or did not use them much.
>>
>
>
>I am actually very familiar with these tools, they are just not
>relevant for large segments of the scientific programming
>community (I hope you do not think MINDO3 could have been
>done using Mathcad :-)

If it is already done in any programming language then it can be easily
added to MathCad Professional.
It's one of it's powers to be easily extended.


Of course no one will insist to use MathCad to simulate nuclear explosion or
do weather forecast or solve aerodynamic equations (aerodynamic tube tests
simulation) in a scaled real-time manner. These *big* kinds of problems
require supercomputers, parallel computation threads using multiprocessors
systems etc.

As Gautier mentioned  MathCad and others such tools are user oriented and
better suited for relatively "small" problems. The border line between
"small" and "big" calculations depends on several different factors and can
be easily estimated.
Some *big* calculations (from numerical point of view)  may be transformed
to *small* ones using symbolic calculation engine or can even be  solved
symbolically which is most preferable.
What is interesting what is "small" now in MathCad was really "big" some
time ago.
Moreover as results of work in the field of artificial intelligence gets
implemented in such products their power is amazingly increasing (again
about AI - symbolic engine- this is what I like most of all).

I do not know much how  Maple and Mathematica  deal with it but MathCad
Professional (only Professional version) is easily extendable with your own
computational functions that become part of it.  In this sense MathCad
Professional is close to other open integrated development systems like
Delphi.
MathCad Professional comes with nice user guide of how to do this and it
supplies all the include files and LIB files with MathCad specific data  for
different compilers (unfortunately no Ada among them - mostly C,CPP  -but
Ada can be used also after translating small C header file to Ada).

As far as for speed all of MathCad built-in  formulas   have been done in
efficient manner (e.g. creating vector V of MAX(i)=100000 elements and then
applying sin(Pi/k) to each element  takes six seconds on my PC.
I did the similar things (applying some function to each vector element)
with vectors of 10000000 elements and no problems ( time taken depends on
amount of phisycal memory - if memory occupied by vector is greater then
this time is affectred by  the memory swapping  with HD)
Dynamic formulars which user creates using MathCad scripting language of
course  have a speed of any scripting language.

So if one can not find what is needed within built-it functions and he/she
is not satisfied with the speed of dynamic formulas (when calculations need
to be done frequently for long period of time) and there is no commercial
libraries in this area from vendor or third parties them one can create
his/her own libraries (DLLs) for use them with MathCad.
After that your numerical sulutions become part of MathCad and will be
combined with all other powers of it.
Very similar to Delphi.

Quote from MathCad documentation:
"To create customized functions, you will first need to create source code
in C or C++,
then compile the source code with a 32-bit compiler. Next, you will link the
object files
together with the MathSoft-provided mcaduser.lib library to create a DLL.
Finally,
you will place your DLL into the userefi subdirectory and add an entry to
user.xml
so that your function appears in the Insert Function dialog box."


As far for speed  of numeric calculations this is only last fraction of all
the time spent to solve the problem.
Previous one is time to express problem  in the language of the tool you are
using.
As MathCad uses human language then this time is relatively small.
If one prefers to do it using any programming language then this will be the
time to code this problem in programming language, build it, debug etc.  and
make sure that everything is correct from all points of view.
The sum of these time and computation time gives you  time to solve the
problem.
From above it is clear where is the border between "small" and "big"
calculations.
Of course there are many other factors that can move this border in both
directions.

Regards.