On Tue, 29 May 2001 21:51:25 +0000 (UTC),
Aaron.Sloman.XX@cs.bham.ac.uk (Aaron Sloman See text for reply
address) wrote:
>Some time ago I noticed that the GSL had become available. I then
>remembered interacting with people doing various kinds of AI
>research who had extolled the benefits of interactive mathematical
>systems (e.g. matlab) that had lots of mathematical capabilities
>pre-packaged so that users did not have to look up algorithms or
>reinvent them and then implement them.
I confess myself a bit puzzled by this, and subsequent, references
to matlab. I've used matlab, and wouldn't have picked it as the
example for an interactive system with lots of mathematical
capabilities. I really don't understand why people like it and
extol the benefits of using it. (And yes, they do exist, I've
met some.)
Don't misunderstand: I'm not denying that matlab is interactive,
and has lots of built-in stuff. But its matrix-manipulation
ancestry made it seem very limited and non-expressive to me. And
I truly do not understand why it is so successful. Can I put
it down to excellent marketing, or is there something about it
which appeals to lots of people but not me?
>Jonathan.Cunningham@tesco.net (Jonathan L Cunningham) writes:
>> Presumably GSL is not an Abomination. (If it is, why would we want
>> to use it?)
>
>(Lots of abominations are very widely used, as you know well.)
Unfortunately, that is true, but doesn't really answer the
question! So I'll answer it myself. Even if it is an abomination,
it is free, and there are no obvious alternatives. (And I also
stick with my "Presumably", too.)
(Someone -- David Young? -- mentioned the NAg library, but since it
is not free, it's not an obvious alternative.)
>> Oh, and does GSL include code for solving LP problems (Linear
>> Programming - a class of optimisation problems)? If so,
>> then I WANT it! :-).
>
>Well, since not everyone has easy and fast access to remote web sites, I
>thought I'd circulate the table of contents from the online GSL manual
>at
>
> http://sources.redhat.com/gsl/ref/gsl-ref_toc.html
>
>Here it is, all subject to the terms of the GNU General Public License.
(huge snip)
FWIW, these are the bits I think should be done first (my personal
wish-list, if you like -- not that I have an immediate use for any
of it, but when I have time ... :-)
> * Fast Fourier Transforms (FFTs)
> + Mathematical Definitions
> + Overview of complex data FFTs
> + Radix-2 FFT routines for complex data
> + Mixed-radix FFT routines for complex data
> + Overview of real data FFTs
> + Radix-2 FFT routines for real data
> + Mixed-radix FFT routines for real data
> + References and Further Reading
Useful, but I think they've been superseded for AI type
applications (Low-level sensory stuff - analysing sounds,
images etc.) by wavelet analysis, which I don't see in the
list.
> * Random Number Generation
(snip)
> * Quasi-Random Sequences
(snip)
> * Random Number Distributions
(snip)
Yes, please. I don't know that they all are, but random thingies
are always fun to have.
And some of them would be useful in Monte Carlo modeling, for
running simulations (even AI simulations!). (I don't include the
Monte Carlo integration stuff, elsewhere in the list, because
that's not the same thing, and is not in my wish list.)
> * Statistics
Statistics, not because I need it, but because it's important.
> * Simulated Annealing
> + Simulated Annealing algorithm
> + Simulated Annealing functions
> + Examples with Simulated Annealing
> o Trivial example
> o Traveling Salesman Problem
Surely there must be lots of poplog stuff covering
simulated annealing already? Would we want the GSL stuff?
> * Linear Algebra
> + LU Decomposition
> + QR Decomposition
> + QR Decomposition with Column Pivoting
> + Singular Value Decomposition
> + Cholesky Decomposition
> + Householder solver for linear systems
> + Tridiagonal Systems
> + References and Further Reading
Which answers my first question. But I want an
easy-to-use beginners version, which presumably could be based on
this stuff. But since I don't know what a Cholesky Decomposition
is, I don't know if I want it.
Jonathan
--
Jonathan L Cunningham
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