Deformable registration in D

[Dave]

Robert Jacques wrote:
> I recently presented at the 49th Annual Meeting of the American 
> Association of Physicists in Medicine an application of a deformable 
> registration algorithm during the general poster discussion session. Of 
> course, the reason I?m posting this here is that I wrote it in D. Or 
> more precisely, I refactored it to D from C++, with some surprising 

What did the audience think of D?

> results. First, the main algorithm dropped to half the lines of code and 
> I was able to completely remove some supporting routines. Second, the 
> numerical stability of the algorithm increased, helping reduce a major 
> fundamental issue/flaw in algorithm (Ah, the joys of a continuous 
> algorithm working on discrete data). And lastly, it ran three to four 
> times slower. The culprit turned out to be the exponential function, 
> which is the crux of the algorithm and also what I assume was 
> responsible for the increased stability. I switched to using an 
> exponential with finite support and regained the speed while keeping the 
> stability. For reference, I was using Microsoft Visual Studio 2003 and 
> D1.x/Phobos on Intel/XP box.
> The code is now open source and available at:
> http://dailabs.duhs.duke.edu/imagequality.html
> And the associated abstract is published in Medical Physics:
> http://www.medphys.org/
> 
> P.S. Thank you Walter and the community for this great language.