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axis & randn


From: John Eaton
Subject: axis & randn
Date: Fri, 3 Nov 1995 00:29:00 -0600

Jerry Lynch <address@hidden> wrote:

: Just out of curiosity, are there any plans for some of the built-in
: functions to be updated in the next release of octave to resemble Matlab 
: updates?

For what it's worth, here are the new entries in the file since 1.1.1.
These are things that are already mostly done, but some items will
need addtional work.


  * Expressions of the form

      A(i,j) = x

    where X is a scalar and the indices i and j define a matrix of
    elements now work as you would expect rather than giving an error.
    I am told that this is how Matlab 5.0 will behave when it is
    released.

  * Indexing of character strings now works.

  * The echo command has been implemented.

  * New method for handling errors:

      try
        BODY
      catch
        CLEANUP
      end_try_catch

    Where BODY and CLEANUP are both optional and may contain any
    Octave expressions or commands.  The statements in CLEANUP are
    only executed if an error occurs in BODY.

    No warnings or error messages are printed while BODY is
    executing.  If an error does occur during the execution of BODY,
    CLEANUP can access the text of the message that would have been
    printed in the builtin constant __error_text__.  This is the same
    as eval (TRY, CATCH) (which may now also use __error_text__) but
    it is more efficient since the commands do not need to be parsed
    each time the TRY and CATCH statements are evaluated.

  * Octave no longer parses the help command by grabbing everything
    after the keyword `help' until a newline character is read.  To
    get help for `;' or `,', now, you need to use the command
    `help semicolon' or `help comma'.

  * Built-in variables that can take values of "true" and "false" can
    now also be set to any nonzero scalar value to indicate "true",
    and 0 to indicate "false".

  * If the new built-in variable `gnuplot_has_multiplot' is nonzero,
    Octave assumes that your copy of gnuplot has the multiplot support
    that is included in recent 3.6beta releases.  It's initial value
    is determined by configure, but it can be changed in your startup
    script or at the command line in case configure got it wrong, or
    if you upgrade your gnuplot installation.

  * New built-in variable `warn_missing_semicolon'.  If nonzero, Octave
    will warn when statements in function definitions don't end in
    semicolons.  The default value is 0.

  * Octave now attempts to continue after floating point excteptions
    or out-of-memory errors.

  * If Octave crashes, it now attempts to save all user-defined
    variables in a file named `octave-core' in the current directory
    before exiting.

  * It is now possible to get the values of individual option settings
    for the dassl, fsolve, lsode, npsol, qpsol, and quad functions
    using commands like

      dassl_reltol = dassl_options ("relative tolerance");

  * The svd() function no longer computes the left and right singular
    matrices unnecessarily.  This can significantly improve
    performance for large matrices if you are just looking for the 
    singular values.

  * The filter() function is now a built-in function.

  * New function randn() returns a pseudo-random number from a normal
    distribution.  The rand() and randn() functions have separate
    seeds and generators.

  * Octave's command-line arguments are now available in the built-in
    variable `argv'.  The program name is also available in the
    variables `program_invocation_name' and `program_name'.  If
    executing a script from the command line (e.g., octave foo.m) or
    using the `#! /bin/octave' hack, the program name is set to the
    name of the script.

  * New built-in variable `completion_append_char' used as the
    character to append to successful command-line completion
    attempts.  The default is " " (a single space).

  * Octave now uses a modified copy of the readline library from
    version 1.14.5 of GNU bash.

  * New built-in variable `beep_on_error'.  If nonzero, Octave will try
    to ring your terminal's bell before printing an error message.
    The default value is 0.

  * New command-line argument --traditional sets the following
    preference variables for compatibility with Matlab:

      PS1                           = ">> "
      PS2                           = ""
      beep_on_error                 = 1
      default_save_format           = "mat-binary"
      define_all_return_values      = 1
      do_fortran_indexing           = 1
      empty_list_elements_ok        = 1
      implicit_str_to_num_ok        = 1
      ok_to_lose_imaginary_part     = 1
      page_screen_output            = 0
      prefer_column_vectors         = 0
      prefer_zero_one_indexing      = 1
      print_empty_dimensions        = 0
      treat_neg_dim_as_zero         = 1
      warn_function_name_clash      = 0
      whitespace_in_literal_matrix  = "traditional"

  * New functions:

      readdir  -- returns names of files in directory as array of strings
      mkdir    -- create a directory
      rmdir    -- remove a directory
      rename   -- rename a file
      umask    -- set permission mask for file creation
      stat     -- get information about a file
      lstat    -- get information about a symbolic link
      more     -- turn the pager on or off
      gammaln  -- alias for lgamma

  * New plotting functions from Vinayak Dutt.  Ones dealing with
    multiple plots on one page require features from gnuplot 3.6beta
    (or later).

      bottom_title -- put title at the bottom of the plot
      mplot        -- multiplot version of plot
      multiplot    -- switch multiple-plot mode on or off
      oneplot      -- return to one plot per page
      plot_border  -- put a border around plots
      subplot      -- position multiple plots on a single page
      subwindow    -- set subwindow position for next plot
      top_title    -- put title at the top of the plot
      zlabel       -- put a label on the z-axis

  * New function, fgetl.  Both fgetl and fgets accept an optional
    second argument that specifies a maximum number of characters to
    read, and the function fgets is now compatible with Matlab.

  * Printing in hexadecimal format now works (format hex).  It is also
    possible to print the internal bit representation of a value
    (format bit).  Note that these formats are only implemented for
    numeric values.

  * Additional structure features:

    -- Name completion now works for structures.

    -- Values and names of structure elements are now printed by
       default.  The new built-in variable `struct_levels_to_print'
       controls the depth of nested structures to print.  The default
       value is 2.

    -- New functions:

       struct_contains (S, NAME) -- returns 1 if S is a structure with
                                    element NAME; otherwise returns 0.

       struct_elements (S)       -- returns the names of all elements
                                    of structure S in an array of strings. 

  * New io/subprocess functions:

      XXX names of functions marked with `*' are subject to change

    * async_system -- start a subprocess asynchronously
    * execute      -- start a subprocess with 2-way communication
      mkfifo       -- create a FIFO special file
      popen        -- open a pipe to a subprocess
      pclose       -- close a pipe from a subprocess
    * sync_system  -- start a subprocess synchronously
      unlink       -- delete a file
      waitpid      -- check the status of or wait for subprocesses

  * New time functions:

      asctime   -- format time structure according to local format
      ctime     -- equivalent to `asctime (localtime (TMSTRUCT))'
      gmtime    -- return time structure corresponding to UTC
      localtime -- return time structure corresponding to local time zone
      strftime  -- print given time structure using specified format
      time      -- return current time

    The `clock' and `date' functions are now implemented in M-files
    using these basic functions.

  * New function getrusage returns a structure containing system
    resource usage statistics.  The `cputime' function is now defined
    in an M-file using getrusage.

  * If it is present, Octave will now use an `ls-R' database file to
    speed up recursive path searching.  Octave looks for a file called
    ls-R in the directory specified by the environment variable
    OCTAVE_DB_DIR.  If that is not set but the environment variable
    OCTAVE_HOME is set, Octave looks in $OCTAVE_HOME/lib/octave.
    Otherwise, Octave looks in the directory $datadir/octave (normally
    /usr/local/lib/octave).

  * Many more bug fixes.

  * ChangeLogs are now kept in each subdirectory.


jwe


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