view PROJECTS @ 2983:145d5acfc68b

[project @ 1997-05-16 03:37:32 by jwe]
author jwe
date Fri, 16 May 1997 03:37:38 +0000
parents e9c24f32f175
children 95e8b5c4824a
line wrap: on
line source

Octave PROJECTS                                          -*- text -*-

Check with for a possibly more current
copy.  Also, if you start working steadily on a project, please let 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 before you start.


  * Merge control stuff.

  * Improve logm, and sqrtm.

  * Improve complex mapper functions.

  * 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.

  * Free QP solver.

  * Free NLP solver.

  * Support for sparse matrices.

  * 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.

  * Implement the following functions:
    -- ppval    -- cross    -- dot

  * Allow user-supplied gradient information to be passed to NPSOL.

  * Actually allow control of the derivative level in NPSOL.  It can
    be changed with npsol_options(), but then NPSOL::do_minimize()
    sets it based on whether gradient and jacobian functions are

  * When constructing NLConst (and other) objects, make sure that
    there are sufficient checks to ensure that the dimensions all

  * Support for FSQP.

  * Convert FSQP style NLP statement to NPSOL style.

  * Convert NPSOL style NLP statement to FSQP style.
    - Look for linear equality constraints, extract corresponding rows
	of C.  The rest are inequality constraints.
    - Look for Nonlinear equality constraints and set up a vector of
	pointers for shuffling.
    - Transform lb <= C*x <= ub, lb != ub, to C*x - ub <= 0 and
	lb - C*x <= 0.  Likewise for lb <= g(x) <= ub.
    - Call FSQP.

  * Optional inputs for fsqp.

  * Allow parameters to be passed through the call to fsolve() to the
    user-supplied function for Matlab compatibility.  Don't place an
    upper limit on the number of arguments.

  * Check matrix classes for proper handling of empty matrices.

  * Force all empty matrices to be 0x0 even when other dimensions have
    been speicified, for compatibility with Matlab, at least when some
    preference variable is set.

  * Make operations with empty matrices produce empty matrices, for
    compatibility with Matlab (but only if Matlab 5 still does things
    this way). For example:  [1, 2] * [] ==> [].

  * Should any ([]) return [] or 0?  What about all ([])?

  * Improve design of ODE, DAE, classes.

  * Make it possible to specify a time which dassl and lsode should
    not integrate past.

  * Add interface to daspk (new version of dassl).

  * 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

  * Add support for +=, -=, etc.

  * Given two vectors x and y of length m and n, implement a function
    outer (x, y, f) that returns an m-by-n matrix with entries
    f (x(i), y(j)).  If f is omitted, multiplication is the default.
    Should probably work for any vectors, not just if x is a column
    vector and y is a row vector.

  * Make it possible to solve b = L \ x efficiently, either by
    providing an explicit function call, or by automatically
    determining that L is triangular.  If it is done automatically,
    provide some means for determining whether Octave has actually
    detected that the matrix is triangular.

  * The polyfit function uses the economy QR factorization, but even
    that can take a lot of time for large datasets.  Consider an
    option to compute the result with inv (A' * A) * A' * y or some
    other faster method.d  Possibly just switch to this method if the
    dataset is larger than some value.

  * Consider making the behavior of the / and \ operators for
    non-square systems compatible with Matlab.


  * Make plotting with plplot work.

  * Fix interface with gnuplot to wait for gnuplot to output any text
    before octave returns a prompt.  Possible by implementing two
    way communication between gnuplot and Octave.

  * Make gsave (and possibly gload) work.  Implement gsave by having it
    also alter the plot command to not use temporary files (perhaps
    with some user-specified template for naming them) and then
    sending a `save' command to gnuplot.

  * It would be nice to be able to check that a plot is currently
    being displayed.

  * Implement clf, gcf, get, set, orient, print, close, etc. in
    Matlab-compatible ways.

  * Make it possible to check the current graphics terminal type.

  * If possible, pass data to gnuplot without using temporary files.

  * If using temporary files, delete them when gnuplot exits.

  * If possible, pass binary data to gnuplot to speed things up.

  * If using gnuplot, consider setting a smaller default for the
    `zero' value (e.g., set zero sqrt (realmin) or something).


  * Improve performance of string functions, particularly for
    searching and replacing.

  * Provide some regex matching functions.

  * 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.

  * Consider making ["test", []] ==> "test", for compatibility with
    Matlab, at least when some set of preferences are set.

Other Data Types:

  * New types (char, short, etc.).

  * 3d matrix stuff.

  * Template functions for mixed-type ops.

  * Stuff for arithmetic using charMatrix, intMatrix, etc.

Graphical User Interface:

  * In an X11 or other windowing environment, allow the user to pop up
    windows for menus and other purposes.  A good place to start might
    be Tk, as long as Tcl is avoided.

  * Add a way to handle events, like alarms, mouse clicks, etc.


  * 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.).

  * Make load and save work for structures.

  * Make load and save look for <file>.mat if only given <file>.

    Potential sticky points:

      - For load, if both foo and foo.mat exist, should it prefer foo
        or foo.mat?  Should the preference depend on the arguments to
        load?  I think it should only prefer .mat files if the
        -mat-binary option is supplied, or if the file foo.mat exists
        but the file foo does not.

      - For save, should it prefer to create foo or foo.mat?  Should
        the preference depend on the arguments to save?  Should the
        default_save_format imply a default preference?  I think it
        should only create .mat files if it is writing Matlab
        compatible files.

  * Move some pr-output stuff to liboctave.

  * Make the cutoff point for changing to packed storage a
    user-preference variable with default value 8192.

  * Save image data in binary format to save space.

  * 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.)

  * Use HDF for binary data.

  * Make ascii load and save work for Inf and NaN.  (This is really a
    problem with the functions for reading floats in the GNU iolib.)

  * 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.


  * Fix the parser so that

      function foo ()
        implicit_str_to_num_ok = 1;
        '#' + 0;

    succeeds, even when implicit_str_to_num_ok is 0 at the time the
    function is parsed.

  * Consider making x(:) work no matter what the value of

  * For indexing operations, allow `$' to indicate the last element.
    For example, b = a (3:$, 1:$-1).  This means b is a, except for
    its first 2 rows and last column.  Note that `$' must be able to
    appear in arbitrarily complex expressions, so copying the the
    current implementation of `:' won't work. 

  * If foo.oct and foo.m both exist in the LOADPATH, Octave will
    always find foo.oct, even if foo.m appears earlier in the list of
    directories.  This should be fixed (in the kpathsearch library) to
    find the first .oct or .m file in the path, and only prefer .oct
    over .m if both files are in the same directory.

  * Fix the grammar to allow structure references and index operations
    for for anonymous expressions.  For example, it should be possible
    to write

      localtime (time ()) . hour;

    to get the current hour.  Likewise, it should be possible to write

      svd (A) (1:13);

    to extract the first 13 singular values of the matrix A.

  * Consider grouping all preference variables in a structure instead
    of further polluting the namespace.  Maybe `'?

  * Rewrite functions in to do the right thing in all cases
    of using readline, forced interactive behavior, echoing of input,

  * Make it possible to redefine built-in variables and functions.
    (Fix whatever it is that is happening with clear for built-in

  * Make it possible to check if a variable is complex.

  * Consider making linspace() and logspace() return the value
    corresponding to the first argument if the number of requested
    points is 1.

  * 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.).

  * Allow `octave -c STRING' to execute commands from STRING then

  * Handle DOS style CRLFs in M files.  This should probably be

  * Make the interpreter run faster.

  * Make it possible to disable or enable all warnings on an
    individual basis from the command line or via some built-in
    structure variable.

  * Warn about complex comparisons?  Could just use double_value() or
    matrix_value() instead of explicit conversions to real types.

  * Make warnings also give some indication about the location of the
    code that triggers the warning.

  * Warn about complex comparisons?  Could just use double_value() or
    matrix_value() instead of explicit conversions to real types.  For
    this to really be useful, some additional information must be
    available to point to the location of the code that triggers the

  * Consider making it possible to have arrays of structures, and some
    way of indexing them.

  * Allow arbitrary lower bounds for array indexing.  (Watch out for
    the additional conflict with zero-one style indexing.)

  * Recursive problems.

  * Improve the way ignore_function_time_stamp works to allow
    selecting by individual directories or functions.  Also,
    optionally allow checking only once between each prompt instead of
    every time the function is called.

  * Make it possible to ask exist() to only look for certain classes
   of variables, functions, files, etc. rather than always looking for

  * Add a command-line option to tell Octave to just do syntax
    checking and not execute statements.

  * Is it necessary for do_binary_op and do_unary_op to be friends of
    the tree_constant class.

  * Clean up symtab and variable stuff.

  * Input stream class for parser files -- must manage buffers for
    flex and context for global variable settings.

  * Make LEXICAL_ERROR have a value that is the error message for
    parse_error() to print?

  * Make it possible to clear dynamically loaded functions.

  * 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

  * What should is_global() return when called for built-in variables?

  * 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;

    would be equivalent to

      function f ()
	  save_prefer_column_vectors = prefer_column_vectors;
	  prefer_column_vectors = something;
	  prefer_column_vectors = save_prefer_column_vectors;

  * Fix all function files to check for bogus inputs (wrong number or
    types of input arguments, wrong number of output arguments).

  * Reduce the memory and time required to parse very large matrix

  * 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.

  * Remove the buffer size limit in octave_read() in

  * Handle arrays with more than two dimensions.

  * Consider making assignment statements like

      M (i_idx, j_idx) = RHS

    produce the value of RHS instead of the value of M.

  * 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...

  * Eliminate force_numeric and make_numeric functions.

  * Is Matrix::fortran_vec() really necessary?

  * print_usage() should set error_state in most cases?

  * Make statements like this

      foo bar baz

    turn into function calls like this:

      foo ("bar", "baz")

    This is pretty ugly and introduces some conflicts.

  * Add a command that works like bash's `builtin' command.

  * Handle comments in parse trees for use with the type command.

  * Make the type command handle script files too, by just reading and
    printing them.

  * Clean up eye, eval, feval, keyboard, input, ones, zeros.

  * Turn off printing when evaluating expressions in an eval()
    statement, for compatibility with Matlab.

  * It would be nice to have an interactive debugger.

  * Make whos report total memory used by variables (and functions?).

  * 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.


  * Add an option to allow saving input from script files in the
    history list.

  * Add an option to include information about the Octave session in
    the history list.  Possibly a time/date stamp and the current
    Octave line number, appended as a comment (users should probably
    be able to control the format).

  * Fix history problems -- core dump if multiple processes are
    writing to the same history file?

Configuration and Installation:

  * Handle USE_READLINE so that --enable-readline will work.

  * Make Octave as independent of the particular readline version as

  * Add an --enable-pathsearch option to configure to make it possible
    to configure and run without kpathsea. 

  * Make configure take more defaults from the environment.  It should
    definitely pay attention to CFLAGS, CXXFLAGS, FFLAGS, etc.

  * Should --enable-lite-kernel imply --enable-shared?

  * Make it possible to configure without readline.

  * 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.

  * Make installation of the static libraries optional.

Documentation and On-Line Help:

  * Document new features.
      -- history-search-{back,for}ward.
      -- try/catch.
      -- 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.

  * Support multiple info files, perhaps allowing one or more in each
    directory in the LOADPATH, so that local collections of M-files
    could be documented with Info.

  * Figure out a good way to have functions and variables documented
    in only one place.

  * Improve help messages for operators and keywords in

  * Make index entries more consistent to improve behavior of `help -i'.

  * Make `help -i' try to find a whole word match first.

  * Allow help for local additions to be accessible with help -i.

  * Make the arrow keys work in the info reader.

  * Update Info to be based on the current Texinfo release.

  * Should info/terminal.c include definitions for PC, BC, UP, and
    ospeed on all systems?

  * 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 LOADPATH, 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

  * Some sort of blurb (2-3 pages) describing Octave in a reasonably
    coherent way, where to get it etc., perhaps formatted pretty,
    i.e. not just text.  Maybe start with the latest Announce file.


  * 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.


  * Move toward using more stuff from standard C++ library.

  * More C++/Fortran cleanups.

  * It is likely that there are still some memory leaks.  Hunt then down
    and plug them. 

  * Better error messages for missing operators?

  * Eliminate duplicate enums in,, and

  * 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.

  * Use STL stuff instead of libg++ lists, maps, and stacks.

  * Eliminate more global variables.

  * Encapsulate readline in a class.  Include interface to stuff like

  * Encapsulate resource stuff in a class.

  * Move procstream to liboctave.

  * Replace more C-style vectors with Array<T> stuff.

  * Use references and classes in more places.

  * Share more code among the various *_options functions.


  * 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

    Perhaps this can be done entirely with a library of M-files.

  * Add a function like strptime() which is the opposite of
    strftime().  A C version is apparently in recent releases of the
    Linux C library.

  * Add a definition to lgrind so that it supports Octave.
    (See for more
    information about lgrind.)


  * Squash bugs.