Scientific computing with D

[Jonathan Crapuchettes]

I agree with you. I use D for complex economic calculations that are run from a 
web site. The great part about D is that other people in the company can easily 
read the code and it is fast enough for what I need to do. I ported a few ATLAS 
C functions and wrapped them with a class, offering high speed matrix 
calculations with excellent usability. Not many other languages allow for this.
JC

Lars Kyllingstad wrote:
> I think D is, or at least could be, the scientific programming language 
> of the future. Here's why -- and possibly how:
> 
> A couple of years ago, I took a university class called Numerical 
> Physics. After finishing the course, I was left with the impression that 
> numerical computing was all about squeezing every last bit of 
> performance out of the computer -- that unnecessary operations and 
> function calls should be avoided at any cost, even if the resulting code 
> is full of nasty hacks and tricks, making it completely illegible and 
> utterly unmaintainable. And of course, in many cases this is true.
> 
> Now, however, I have a bit more experience in the field and I know that 
> it is not always so. In numerics, as in other areas of programming, it 
> is a trade-off between development time and execution time. 
> Traditionally, if one has a desperate need for speed (sorry), one uses 
> FORTRAN, C or C++. The programs run very fast, but can be hard to 
> develop, debug and maintain. For less processor-intensive tasks one uses 
> Matlab, Mathematica, etc. which have a lot of built-in functionality and 
> make for rapid development, but programs run at a snail's pace.
> 
> With D one has the best of both worlds. I've used both C++ and 
> Mathematica for numerics in the past, but now I use D almost 
> exclusively. I find it a lot easier (and more fun) to code in than C++, 
> and I spend a LOT less time debugging my programs. On the other hand, 
> calculations that would take an entire day in Mathematica are finished 
> in a matter of minutes using D.
> 
> It's a fact that D programs don't have the performance of C(++) ones, 
> but that, I think, is just a matter of time (pun not intended). It's a 
> relatively new language, and the compilers are still somewhat immature.
> 
> The one thing I miss the most, however, and which I think is necessary 
> for D to "take off" as a scientific language, is a native D scientific 
> library.
> 
> Searching dsource, I find that many nice modules and libraries have been 
> made already:
>  - MultiArray (Bill, Fawzi)
>  - dstat (dsimcha)
>  - blip (Fawzi)
>  - MathExtra, BLADE (Don)
>  - Scrapple/backmath (BCS)
>  - Scrapple/units (BCS)
>  - bindings to GSL, BLAS, etc.
>  - ...and probably more
> 
> Myself, I've written/ported some routines for numerical differentiation 
> and integration, one- and multi-dimensional root-finding and some very 
> basic linear algebra, but so far only for personal use. Currently, I'm 
> thinking of porting QUADPACK to D.
> 
> I think it would be really nice if many or all of the above mentioned 
> things could be collected in a single library, together with all kinds 
> of other stuff. Something like the GSL, only written in D. (In my head 
> it's called SciD. At first I thought of DSL - D Scientific Library - but 
> that acronym is used all over the place.) I haven't the time, nor the 
> skills, to write an entire such library myself, but I'd be happy to 
> contribute where I can.
> 
> Here are some design goals I find important:
>  - sensible, logical and tidy package hierarchy
>  - access to high-level functionality for rapid development
>  - access to low-level functionality for performance
>  - make use of D's awesome compile-time functionality
>  - reusability, pluggability and extensibility
> 
> (By the last point I mean that if one method doesn't work it should be 
> quickly and easily replaceable in code with something else. This is 
> achievable through the use of templates and interfaces, and ties in with 
> the second point.)
> 
> So, what do you think? Am I making any sense? Am I the only one 
> interested in these things?
> 
> All of the above are, of course, my personal opinions. What are yours?
> 
> 
> -Lars