Check with maintainers@octave.org for a possibly more current copy. Also, if you start working steadily on a project, please let maintainers@octave.org know. We might have information that could help you; we'd also like to send you the GNU coding standards.
This list is not exclusive -- there are many other things that might be good projects, but it might instead be something we already have, so check with maintainers@octave.org before you start.
Numerical
* Improve logm, and sqrtm.
* Improve complex mapper functions. See W. Kahan, `Branch Cuts for
Complex Elementary Functions, or Much Ado About Nothing's Sign
Bit' (in The State of the Art in Numerical Analysis, eds. Iserles
and Powell, Clarendon Press, Oxford, 1987) for explicit
trigonometric formulae.
* Make functions like gamma() return the right IEEE Inf or NaN
values for extreme args or other undefined cases.
* Handle complex values in fread and fwrite.
* Support for lp_solve for linear programming problems.
* Improve sqp.
* Fix CollocWt to handle Laguerre polynomials. Make it easy to
extend it to other polynomial types.
* Add optional arguments to colloc so that it's not restricted to
Legendre polynomials.
* Fix eig to also be able to solve the generalized eigenvalue
problem, and to solve for eigenvalues and eigenvectors without
performing a balancing step first.
* Move rand, eye, xpow, xdiv, etc., functions to the matrix classes.
* Use octave_allocator for memory management in Array classes once
g++ supports static member templates.
* When constructing NLConst (and other) objects, make sure that
there are sufficient checks to ensure that the dimensions all
conform.
* Improve design of ODE, DAE, classes.
* Extend meaning of .* to include v .* M or M .* v (where v is a
column vector with the same number of rows as M) to scale rows of
M by elements of v. Similarly, if w is a row vector with as many
columns as M, then either w .* M or M .* w scales the columns of
M.
* Make QR more memory efficient for large matrices when not all the
columns of Q are required (apparently this is not handled by the
lapack code yet).
* Consider making the behavior of the / and \ operators for
non-square systems compatible with Matlab. Currently, they return
the minimum norm solution from DGELSS, which behaves differently.
Sparse Matrices
* Improve QR factorization functions, using idea based on CSPARSE
cs_dmsol.m
* Implement fourth argument to the sprand and sprandn, and addition
arguments to sprandsym that the leading brand implements.
* Sparse logical indexing in idx_vector class so that something like
"a=sprandn(1e6,1e6,1e-6); a(a<1) = 0" won't cause a memory overflow.
* Make spalloc(r,c,n) actually create an empty sparse with n non-zero
elements? This allows something like
sm = spalloc (r,c,n)
for j=1:c
for i=1:r
tmp = foo (i,j);
if (tmp != 0.)
sm (i,j) = tmp;
endif
endfor
endfor
actually make sense. Otherwise the above will cause massive amounts
of memory reallocation.
The fact is that this doesn't make sense in any case as the assign
function makes another copy of the sparse matrix. So although spalloc
might easily be made to have the correct behaviour, the first assign
will cause the matrix to be resized !!! There seems to be no simple
way to treat this but a complete rewrite of the sparse assignment
functions...
* Other missing Functions
- symmmd Superseded by symamd
- colmmd Superseded by colamd
- treelayout
- cholinc
- condest
- bicg Can this be taken from octave-forge?
- bicgstab
- cgs
- gmres
- lsqr
- minres
- qmr
- symmlq
- spaugment
Strings
* Improve performance of string functions, particularly for
searching and replacing.
* Convert string functions to work on string arrays.
* Make find work for strings.
* Consider making octave_print_internal() print some sort of text
representation for unprintable characters instead of sending them
directly to the terminal. (But don't do this for fprintf!)
* Consider changing the default value of string_fill_char from SPC
to NUL.
Other Data Types
* Template functions for mixed-type ops.
Input/Output
* Make fread and fwrite work for complex data. Iostreams based
versions of these functions would also be nice, and if you are
working on them, it would be good to support other size
specifications (integer*2, etc.).
* Move some pr-output stuff to liboctave.
* Make the cutoff point for changing to packed storage a
user-preference variable with default value 8192.
* Make it possible to load other image formats (ppm, pbm, etc. would
probably be best since there are already filters to convert to
these formats from others.)
* Complain if there is not enough disk space available (I think
there is simply not enough error checking in the code that handles
writing data).
* Make it possible to tie arbitrary input and output streams
together, similar to the way iostreams can be tied together.
Interpreter
* Allow customization of the debug prompt.
* For the keyboard function, parse return (or quit) more
intelligently so that something like
debug> x = 1; return
will work as expected.
* Handle multi-line input at the keyboard/debug prompt correctly.
* Fix the parser so that
if (expr) 'this is a string' end
is parsed as IF expr STRING END.
* Clean up functions in input.cc that handle user input (there
currently seems to be some unnecessary duplication of code and it
seems overly complex).
* Consider allowing an arbitrary property list to be attached to any
variable. This could be a more general way to handle the help
string that can currently be added with document.
* Allow more command line options to be accessible as built-in
variables (--echo-commands, etc.).
* Make the interpreter run faster.
* Allow arbitrary lower bounds for array indexing.
* Improve performance of recursive function calls.
* Improve the way ignore_function_time_stamp works to allow
selecting by individual directories or functions.
* Add a command-line option to tell Octave to just do syntax
checking and not execute statements.
* Clean up symtab and variable stuff.
* Input stream class for parser files -- must manage buffers for
flex and context for global variable settings.
* make parser do more semantic checking, continue after errors when
compiling functions, etc.
* Make LEXICAL_ERROR have a value that is the error message for
parse_error() to print?
* Add a run-time alias mechanism that would allow things like
alias fun function_with_a_very_long_name
so that function_with_a_very_long_name could be invoked as
fun.
* Allow local changes to variables to be written more compactly than
is currently possible with unwind_protect. For example,
function f ()
local prefer_column_vectors = something;
...
endfunction
would be equivalent to
function f ()
save_prefer_column_vectors = prefer_column_vectors;
unwind_protect
prefer_column_vectors = something;
...
unwind_protect_cleanup
prefer_column_vectors = save_prefer_column_vectors;
end_unwind_protect
endfunction
* Fix all function files to check for bogus inputs (wrong number or
types of input arguments, wrong number of output arguments).
* Handle options for built-in functions more consistently.
* Too much time is spent allocating and freeing memory. What can be
done to improve performance?
* Error output from Fortran code is ugly. Something should be done to
make it look better.
* It would be nice if output from the Fortran routines could be
passed through the pager.
* Attempt to recognize common subexpressions in the parser.
* Consider making it possible to specify an empty matrix with a
syntax like [](e1, e2). Of course at least one of the expressions
must be zero...
* Is Matrix::fortran_vec() really necessary?
* Add a command that works like bash's builtin command.
* It would be nice to have an interactive debugger.
* Rewrite whos and the symbol_record_info class. Write a built-in
function that gives all the basic information, then write who and
whos as M-files.
* On systems that support matherr(), make it possible for users to
enable the printing of warning messages.
* Make it possible to mark variables and functions as read-only.
* Make it possible to write a function that gets a reference to a
matrix in memory and change one or more elements without
generating a second copy of the data.
* Use nanosleep instead of usleep if it is available? Apparently
nanosleep is to be preferred over usleep on Solaris systems.
History
* Add an option to allow saving input from script files in the
history list.
* The history command should accept two numeric arguments to
indicate a range of history entries to display, save or read.
* Avoid writing the history file if the history list has not
changed.
* Avoid permission errors if the history file cannot be opened for
writing.
* Fix history problems -- core dump if multiple processes are
writing to the same history file?
Configuration and Installation
* Add an --enable-pathsearch option to configure to make it possible
to configure and run without kpathsea.
* Makefile changes:
-- eliminate for loops
-- define shell commands or eliminate them
-- verify distclean
-- consolidate targets
* Make it possible to configure so that installed binaries and
shared libraries are stripped.
* Create a docs-only distribution?
Documentation and On-Line Help
* Document new features.
-- history-search-{back,for}ward.
-- Other stuff mentioned in the NEWS file.
* Improve the Texinfo Documentation for the interpreter. It would
be useful to have lots more examples, to not have so many forward
references, and to not have very many simple lists of functions.
* The docs should mention something about efficiency and that using
array operations is almost always a good idea for speed.
* Texinfo documentation for the C++ classes.
* Make index entries more consistent to improve behavior of help -i.
* Make help -i try to find a whole word match first.
* Clean up help stuff.
* Demo files.
* As the number of m-files with octave grows perhaps a 'Contents.m'
file for each toolbox (directory) would be appropriate so one
knows exactly what functions are in a toolbox with a quick look.
It would be best to generate information for each function directly
from the M-files, so that the information doesn't have to be
duplicated, and will remain current if the M-files change. It
would also be best to do as much of this as possible in an M-file,
though I wouldn't mind adding some basic support for listing the
names of all the directories in the load path, and the names of all
the M-files in a given directory if that is needed.
Also make it possible to recursively search for Contents files:
help dir -- Contents from dir
help dir// -- Contents from dir and all its subdirectories
help dir1/dir2 -- Contents from dir2 which is under dir1
Tests
* Improved set of tests:
-- Tests for various functions. Would be nice to have a test file
corresponding to every function.
-- Tests for element by element operators:
+ - .* ./ .\ .^ | & < <= == >= > != !
-- Tests for boolean operators: && ||
-- Tests for other operators: * / \ ' .'
-- Tests from bug reports.
-- Tests for indexed assignment. Need to consider the following:
o fortran-style indexing
o zero-one indexing
o assignment of empty matrix as well as values
o resizing
* Tests for all internal functions.
Programming
* Better error messages for missing operators?
* Eliminate duplicate enums in pt-exp.cc, pt-const.cc, and ov.cc.
* Handle octave_print_internal() stuff at the liboctave level. Then
the octave_value classes could just call on the print() methods
for the underlying classes.
* As much as possible, eliminate explicit checks for the types of
octave_value objects so that user-defined types will automatically
do the right thing in more cases.
* Only include config.h in files that actually need it, instead of
including it in every .cc file. Unfortunately, this might not be
so easy to figure out.
* GNU coding standards:
-- Add a Makefile target to the Makefiles.
-- Comments on #else and #endif preprocessor commands.
-- Change error message format to match standards everywhere.
* Eliminate more global variables.
* Move procstream to liboctave.
* Use references and classes in more places.
* Share more code among the various *_options functions.
Miscellaneous
* Implement some functions for interprocess communication: bind,
accept, connect, gethostbyname, etc.
* The installation process should also install octave.el. This
needs to detect the appropriate Emacs binary to use to
byte-compile the .el file. Following GNU Emacs philosophy,
installation would be into $(prefix)/share/emacs/site-lisp by
default, but it should be selectable.
* The ability to transparently handle very large files:
Juhana K Kouhia wrote:
If I have a one-dimensional signal data with the size 400
Mbytes, then what are my choices to operate with it:
* I have to split the data
* Octave has a virtual memory on its own and I don't have to
worry about the splitting.
If I split the data, then my easily programmed processing
programs will become hard to program.
If possible, I would like to have the virtual memory system in
Octave i.e. the all big files, the user see as one big array or
such. There could be several user selectable models to do the
virtual memory depending on what kind of data the user have (1d,
2d) and in what order they are processed (stream or random
access).
Perhaps this can be done entirely with a library of M-files.
* An interface to gdb.
Michael Smolsky wrote:
I was thinking about a tool, which could be very useful for me
in my numerical simulation work. It is an interconnection
between gdb and octave. We are often managing very large arrays
of data in our fortran or c codes, which might be studied with
the help of octave at the algorithm development stages. Assume
you're coding, say, wave equation. And want to debug the
code. It would be great to pick some array from the memory of
the code you're develloping, fft it and see the image as a
log-log plot of the spectral density. I'm facing similar
problems now. To avoid high c-development cost, I develop in
matlab/octave, and then rewrite into c. It might be so much
easier, if I could off-load a c array right from the debugger
into octave, study it, and, perhaps, change some [many] values
with a convenient matlab/octave syntax, similar to
a(:,50:250)=zeros(100,200), and then store it back into the
memory of my c code.
* Add a definition to lgrind so that it supports Octave.
(See http://www.tex.ac.uk/tex-archive/support/lgrind/ for more
information about lgrind.)
Always
* Squash bugs.