Re: [dev] a suckless computer algebra system

On Fri, Nov 20, 2009 at 02:57:24PM +0000, David Tweed wrote:
> I was pointing out more how the simple-minded software metrics would
> condemn you to around about the level of performance acheived by the
> reference LAPACK (white bars) in the paper referenced, which to my
> mind suggests there's a flaw in the software metrics. I'd also query
> that the code quality is terrible in most numerical software: what I'd
> say is that they've got a task to acheive (ie, using as much of the
> computing power as possible) and make the software as simple and
> maintainable as it can be given the task. (What they don't generally
> do is say "if we reduce what portion of the task we'll implement for
> users, we get wonderfully simple code".)

I think there is no misunderstanding here; the "suckless metrics" do not
apply here. But given that this is a suckless list, with the "terrible code
quality" I meant that numerical software is often terrible against
conventional metrics of code quality; cryptic, hard to read and understand,
full of little "hacks", difficult to change and maintain, badly formatted,
etc.

Take the aspects of software quality mentioned in ISO 9126-1:

* Functionality (suitability, accuracy, compliance, security, etc.)
* Reliability (maturity, recoverability, fault tolerance, etc.)
* Usability (learnability, understandability, operability, etc.)
* Efficiency (time and space performance, etc.)
* Maintainability (stability, analyzability, testability, etc.)
* Portability (installability, replaceability, adaptability, etc.)

Against these abstract concepts of general software quality, I'd say that
numerical software is generally par excellence in some aspects, but terrible
in others.

- Jukka.
Received on Fri Nov 20 2009 - 15:20:22 UTC