todo

开放gsl矩阵运算

Main Todo Items
===============

We are looking for volunteers to do the following tasks,

* [Consult the TODO files in each directory first for specific
requirements.]

* Make a web page at www.gnu.org

* Arrange for RPMs to be uploaded to Redhat's contrib area

* Document dht

* Switch to library interface versioning for libtool (eventually),
provide better GSL_VERSION_MAJOR, GSL_VERSION_MINOR macros.

* add Fresnel Integrals to specfunc.  See TOMS 723 + 2 subsequent
errata.

* make mode variables consistent in specfunc -- some seem to be
unnecessary from performance point of view since the speed difference
is negligible.

* Complex polynomial solvers (Got Newton-Mueller from
[e-mail], still to add (BJG)).

* Reorganize siman interfaces to allow iterative use.

* Add a GSL_ERROR_MODE environment variable for choosing error
behavior at runtime.

* Implement N-d histograms (Simone Piccardi <[e-mail]> is
working on something here).

* More tests. We should (at least) have a test for every error
condition.  Use GCOV to improve coverage.

* Annotate the header files with GAMS classifications

* Use pkg-config from GNOME, preferably the C version when that is
working.

* Provide g-wrap wrappers for guile

* Provide a run-time expression evaluator for interactive programs
where the user can provide formulas as strings.  Keith Briggs
recommended formulc2.22 which he had found useful in several projects.
http://www.cs.brandeis.edu/~hhelf/formu/formulc.html. It is LGPL.
Alternatively, the source code for GDB contains yacc grammars and
evaluators for expressions in various languages, so that would be
another way to go.  It would have the advantage of following the
language standards.  If I was going to write something from scratch I
would think about using that as a base, as the full set of operators
are already included with the correct precedence rules. Being able to
evaluate C and Fortran expressions could be useful.

Before Each Release
===================

* Make sure that all #defines are fully wrapped in ()'s, especially
the outermost layer which may have been missed. Everything should be
of the form #define foo(x) (....) so there is no possibility of bad
parsing.

* Clean up the ordering of lines in the Makefile.am's so that they are
all consistent. At the moment the lines are in any order. Also get rid
of make strict targets, since it's better to define a shell alias to
do that.  Files with strict target are 

    specfunc/Makefile.am

* Make all internal functions static, and have all exported functions
& variables prefixed with gsl_ or GSL_. Useful command for checking this: nm -A -g -P */*.a  | perl -a -n -e 'print if $F[1] !~ /gsl_/ && $F[2] ne "U"'

* Make sure config.h is used consistently. This is especially relevant
for HAVE_INLINE use in installed headers.  

 grep config.h gsl/*.h    --- shouldn't match anything
 grep -L config.h */*.c m| grep -v _source  --- gives files not using config.h

* Make the return value EINVAL vs EDOM consistent for invalid
parameters. EDOM means a domain error (i.e. float or mathematically
undefined), EINVAL means invalid (i.e. zero length)

* Change return 0 to return GSL_SUCCESS, and return -1 to GSL_FAILURE
throughout, where appropriate. Similarly change any if(...) checks of
return values to use == GSL_SUCCESS, if they are checking for zero.
N.B. want to be careful about accidentally omitting error conditions
if using something like == GSL_FAILURE when function returns a
different error code.

Wishlist or vague ideas
=======================

* An example chapter on how to link GSL code with Python

* Provide an interface to LAPACK, as for BLAS?  Clarify the license
for LAPACK first, their web page is vague on what the license terms
are.  Some parts of LAPACK are included in octave so maybe the Octave
maintainers will know more.

* Public domain or free texts which could be distributed with GSL:
     
Abramowitz and Stegun, "Handbook of Mathematical Functions" appears to
be public domain.

Devroye's book on Random Variates (1st ed) is/was in the public
domain.  The troff source has been lost, unfortunately, but he says we
could scan it in if anyone would like to do that. It is 800 pages so a
spare copy of the book that could have the binding removed would be
needed, plus a scanner with an Automatic Document Feeder.

ACM TOMS articles in the printed journal have the following copyright notice,

    "Permission to copy without fee all or part fo this material is
    granted provided that the copies are made not made or distributed for
    direct commercial advantage, the ACM copyright notice and the title of
    the publication and its date appear, and notice is given by
    permisision of the association for Computing Machinery. To copy
    otherwise, or to republish, requires a fee and/or specific
    permission."

Wonder what this might mean with regard to being scanned and
distributed (??), presumably it is considered "republication" and so
requires permission.  The versions downloaded from their server
explicitly forbid redistribution (natch).

* Investigate complex support in GCC: Operations like sin(z) silently
convert argument to double, losing the imaginary part. This is
mentioned in CEPHES documentation in 1998 with a patch to generate a
warning.  What happened? (Does it now work with gcc-3.0?)

* Go through the matrix and vector functions systematically and decide
what should be provided outside of BLAS.

* Standardize function names, in particular VERB vs NOUN (e.g. _invert
vs _inverse). Also adopt a convection for functions which can operate
in place vs use of workspace (e.g linalg_solve functions).

* Change from gsl-ref.texi to gsl.texi since it is the main file?
Also, put under dir section "Math" (which seems to be the appropriate
one for Debian, as Octave, Gnuplot etc are in that)

* Use GNU Free Documentation License for reference manual?

* Remove error stream stuff?? It is hardly used.

* Extend histogram routines as described in recent discussion

* Check that there are no conflicts when linking with Lapack. CBLAS, ATLAS

* Make a sorted datatype for the median and quantile functions so that
the user can be prevented from passing unsorted data, which is not
checked for.

* Eliminate use of volatile where it has been used to force rounding
(integration/). It is better to write the code to avoid dependence on
rounding.

* Optimization/error for dest == src as appropriate

* Constant objects (like gsl_roots_fsolver_brent) ought to have
constant pointers (const gsl_roots_fsolver_type * const
gsl_roots_fsolver_brent)??

* Add swig.i files and swig demos so that swig can be run more easily

* Redesign the interface to iterative functions to use an init/do-while
construct (Mostly done).

* Add a vector layer to statistics and ffts, sometime in the future.

* Look at www.vsipl.org