[liblamp-developers] First steps

[Philipp K. <phi...@ph...>]

Hiho,


Alright, so let's talk english. Didn't know that it's an english
mailinglist, sorry for that.
Just wanna write some thoughts about your last email, Stefan:

1) It surely has to be very abstract, however, this will make everything
alot more difficult. As I've seen, you've already implemented the SI-System.
Just want to mention that it's prolly not the most used system in the world;
the cgs-system is probably used more often, especially as it's kinda common
in the USA. So we should always remember to write the code for all
unit-systems (e.g. theoretical physicists usually use "god-given units", i.e.
c = \epsilon_0 = \mu_0 = \hbar = ... = 1, if I remember correctly).

2) Using prewritten units for the numerical part is prolly a good first
step, however, these units are usually very difficult to use and make things
much more complex and not always faster. I wasn't able to use a lot of these
libraries, as they are usually licensed under the GPL and my thesis programs
are close-sourced, however, the one I have used didnt make things faster and
so I've written most of the stuff myself. I've written quite fast classes
(in FreePascal tho) for vectors and matrices. Solving ODEs will probably be
the most difficult stuff and shouldnt be underestimated (Euler, Runge-Kutta
etc. will NOT work for alot, if not most, of the ODEs you'll see in "real
physics".)

3) Implementing mechanics at first is probably correct, however, I would NOT
use Lagrange for it, but Hamilton or Hamilton-Jacobi. Using Hamilton has the
big advantage that you can most likely use the same classes (if written
abstract) for thermodynamics, statistical physics and electrodynamics (among
others), as all of these fields can be described using the basic "field
theory". As Newton, Lagrange and Hamilton is basically the same, atleast
from a theoretical aspect (the only difference is that it's much more easy
to solve problems with Lagrange / Hamilton for _us_), it could perhaps not
make any difference, however, I'm not really into this stuff ATM.


So far,

Philipp


P.S. If you wanna know more about mentioned stuff, feel free to ask. If you
need advise for good books, feel free to ask. If you wanna meet in any way:
sure! ;)