web-octave: NEWS-1.html comparison

comparison NEWS-1.html @ 94:e8fc61e077fc

Merged closed branch "kai" into default.

author	Kai T. Ohlhus <k.ohlhus@gmail.com>
date	Tue, 01 Nov 2016 01:06:10 +0100
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+<!doctype html public "-//IETF//DTD HTML Strict//EN">
+<html>
+<head>
+<title> Changes in Octave version 1 </title>
+</head>
+<body>
+<h1> News for Octave Version 1 </h1>
+<hr>
+<h2>Summary of changes for version 1.1.1</h2>
+<pre>
+* New built-in variables, default_return_value and
+define_all_return_values.
+If define_all_return_values is set to "false", Octave does not do
+anything special for return values that are left undefined, and
+you will get an error message if you try to use them.  For
+example, if the function
+function [x, y] = f ()
+y = 1;
+endfunction
+is called as
+octave:13> [a, b] = f ()
+Octave will print an error message for the attempt to assign an
+undefined value to `a'.
+This is incompatible with Matlab, which will define the return
+variable `x' to be the empty matrix.  To get the Matlab-like
+behavior, you can set the variable define_all_return_values to
+"true" (the default is "false") and default_return_value to `[]'
+(the default).  Then, any return values that remain undefined when
+the function returns will be initialized to `[]'.
+If the function is called without explicitly asking for an output,
+it will succeed.  This behavior is compatible and unchanged from
+previous versions of Octave.
+* New built-in variable suppress_verbose_help_message.  If set to
+"true", Octave will not add additional help information to the end
+of the output from the help command and usage messages for
+built-in commands.  The default value is "false".
+* New built-in variable PS4 is used as the prefix of echoed input
+(enabled with the --echo-input (-x) option).
+* The function size() now accepts an optional second argument.
+* Output from `save - ...' now goes through the pager.
+* The break statement may also be used to exit a function, for
+compatibility with Matlab.
+* The directory tree for installing Octave is now closer to
+conforming with the current GNU standards.
+* More bug fixes.
+</pre>
+<h2>Summary of changes for version 1.1.0</h2>
+<pre>
+* Octave now requires g++ 2.6.3 or later.  This change is necessary
+to make template instantiations cleaner, and to avoid having to
+have special cases in the code for earlier versions of gcc.
+* A new data structure type has been added.  The implementation uses
+an associative array with indices limited to strings, but the
+syntax is more like C-style structures.  here are some examples of
+using it.
+Elements of structures can be of any type, including structures:
+octave:1> x.a = 1;
+octave:2> x.b = [1, 2; 3, 4];
+octave:3> x.c = "string";
+octave:4> x
+x =
+<structure: a b c>
+octave:5> x.a
+x.a = 1
+octave:6> x.b
+x.b =
+1  2
+3  4
+octave:7> x.c
+x.c = string
+octave:8> x.b.d = 3
+x.b.d = 3
+octave:9> x.b
+x.b =
+<structure: d>
+octave:10> x.b.d
+x.b.d = 3
+Functions can return structures:
+octave:1> a = rand (3) + rand (3) * I;
+octave:2> function y = f (x)
+> y.re = real (x);
+> y.im = imag (x);
+> endfunction
+octave:3> f (a)
+ans =
+<structure: im re>
+octave:4> ans.im
+ans.im =
+0.093411  0.229690  0.627585
+0.415128  0.221706  0.850341
+0.894990  0.343265  0.384018
+octave:5> ans.re
+ans.re =
+0.56234  0.14797  0.26416
+0.72120  0.62691  0.20910
+0.89211  0.25175  0.21081
+Return lists can include structure elements:
+octave:1> [x.u, x.s, x.v] = svd ([1, 2; 3, 4])
+x.u =
+-0.40455  -0.91451
+-0.91451   0.40455
+x.s =
+5.46499  0.00000
+0.00000  0.36597
+x.v =
+-0.57605   0.81742
+-0.81742  -0.57605
+octave:8> x
+x =
+<structure: s u v>
+This feature should be considered experimental, but it seems to
+work ok.  Suggestions for ways to improve it are welcome.
+* Octave now supports a limited form of exception handling modelled
+after the unwind-protect form of Lisp:
+unwind_protect
+BODY
+unwind_protect_cleanup
+CLEANUP
+end_unwind_protect
+Where BODY and CLEANUP are both optional and may contain any
+Octave expressions or commands.  The statements in CLEANUP are
+guaranteed to be executed regardless of how control exits BODY.
+This is useful to protect temporary changes to global variables
+from possible errors.  For example, the following code will always
+restore the original value of the built-in variable
+do_fortran_indexing even if an error occurs while performing the
+indexing operation.
+save_do_fortran_indexing = do_fortran_indexing;
+unwind_protect
+do_fortran_indexing = "true";
+elt = a (idx)
+unwind_protect_cleanup
+do_fortran_indexing = save_do_fortran_indexing;
+end_unwind_protect
+Without unwind_protect, the value of do_fortran_indexing would not
+be restored if an error occurs while performing the indexing
+operation because evaluation would stop at the point of the error
+and the statement to restore the value would not be executed.
+* Recursive directory searching has been implemented using Karl
+Berry's kpathsea library.  Directories below path elements that
+end in // are searched recursively for .m files.
+* Octave now waits for additional input when a pair of parentheses
+is `open' instead of giving an error.  This allows one to write
+statements like this
+if (big_long_variable_name == other_long_variable_name
+|| not_so_short_variable_name > 4
+&& y > x)
+some (code, here);
+without having to clutter up the if statement with continuation
+characters.
+* Continuation lines are now allowed in string constants and are
+handled correctly inside matrix constants.
+* Both `...{whitespace}\n' and `\{whitespace}\n' can be used to
+introduce continuation lines, where {whitespace} may include
+spaces, tabs and comemnts.
+* The script directory has been split up by topic.
+* Dynamic linking mostly works with dld.  The following limitations
+are known problems:
+-- Clearing dynamically linked functions doesn't work.
+-- Dynamic linking only works with dld, which has not been ported
+to very many systems yet.
+-- Configuring with --enable-lite-kernel seems to mostly work to
+make nonessential built-in functions dynamically loaded, but
+there also seem to be some problems.  For example, fsolve seems
+to always return info == 3.  This is difficult to debug since
+gdb won't seem to allow breakpoints to be set inside
+dynamically loaded functions.
+-- Octave uses a lot of memory if the dynamically linked functions
+are compiled with -g.  This appears to be a limitation with
+dld, and can be avoided by not using -g to compile functions
+that will be linked dynamically.
+* fft2 and ifft2 are now built-in functions.
+* The `&&' and `||' logical operators are now evaluated in a
+short-circuit fashion and work differently than the element by
+element operators `&' and `|'.  See the Octave manual for more
+details.
+* Expressions like 1./m are now parsed as 1 ./ m, not 1. / m.
+* The replot command now takes the same arguments as gplot or
+gsplot (except ranges, which cannot be respecified with replot
+(yet)) so you can add additional lines to existing plots.
+* The hold command has been implemented.
+* New function `clearplot' clears the plot window.  The name `clg'
+is aliased to `clearplot' for compatibility with Matlab.
+* The commands `gplot clear' and `gsplot clear' are equivalent to
+`clearplot'.  (Previously, `gplot clear' would evaluate `clear' as
+an ordinary expression and clear all the visible variables.)
+* The Matlab-style plotting commands have been improved.  They now
+accept line-style arguments, multiple x-y pairs, and other plot
+option flags.  For example,
+plot (x, y, "@12", x, y2, x, y3, "4", x, y4, "+")
+results in a plot with
+y  plotted with points of type 2 ("+") and color 1 (red).
+y2 plotted with lines.
+y3 plotted with lines of color 4.
+y4 plotted with points which are "+"s.
+the help message for `plot' and `plot_opt' provide full
+descriptions of the options.
+* NaN is now dropped from plot data, and Inf is converted to a
+very large value before calling gnuplot.
+* Improved load and save commands:
+-- The save and load commands can now read and write a new binary
+file format.  Conversion to and from IEEE big and little endian
+formats is handled automatically.  Conversion for other formats
+has not yet been implemented.
+-- The load command can now read Matlab .mat files, though it is
+not yet able to read sparse matrices or handle conversion for
+all data formats.
+-- The save command can write Matlab .mat files.
+-- The load command automatically determines the save format
+(binary, ascii, or Matlab binary).
+-- The default format for the save command is taken from the
+built-in variable `default_save_format'.
+-- The save and load commands now both accept a list of globbing
+patterns so you can easily load a list of variables from a
+file.
+-- The load command now accepts the option -list, for listing the
+variable names without actually loading the data.  With
+-verbose, it prints a long listing.
+-- The load command now accepts the option -float-binary, for
+saving floating point data in binary files in single precision.
+* who and whos now accept a list of globbing patterns so you can
+limit the lists of variables and functions to those that match a
+given set of patterns.
+* New functions for manipulating polynomials
+compan     -- companion matrix corresponding to polynomial coefficients
+conv       -- convolve two vectors
+deconv     -- deconvolve two vectors
+roots      -- find the roots of a polynomial
+poly       -- characteristic polynomial of a matrix
+polyderiv  -- differentiate a polynomial
+polyinteg  -- integrate a polynomial
+polyreduce -- reduce a polynomial to minimum number of terms
+polyval    -- evaluate a polynomial at a point
+polyvalm   -- evaluate a polynomial in the matrix sense
+residue    -- partial fraction expansion corresponding to the ratio
+of two polynomials
+* New functions for manipulating sets
+create_set   -- create a set of unique values
+complement   -- find the complement of two sets
+intersection -- find the intersection of two sets
+union        -- find the union of two sets
+* New elementary functions:
+acot   acoth   acsc   acsch
+asec   asech   cot    coth
+csc    csch    log2   sec
+sech
+* New special functions:
+beta   -- beta function
+betai  -- incomplete beta function
+gammai -- incomplete gamma function
+* New image processing functions:
+colormap  -- set and return current colormap
+gray      -- set a gray colormap
+gray2ind  -- image format conversion
+image     -- display an image
+imagesc   -- scale and display an image
+imshow    -- display images
+ind2gray  -- image format conversion
+ind2rgb   -- image format conversion
+loadimage -- load an image from a file
+ntsc2rgb  -- image format conversion
+ocean     -- set a color colormap
+rgb2ind   -- image format conversion
+rgb2ntsc  -- image format conversion
+saveimage -- save an image to a file
+* New time and date funcitons:
+tic          -- set wall-clock timer
+toc          -- get elapsed wall-clock time, since timer last set
+etime        -- another way to get elapsed wall-clock time
+cputime      -- get CPU time used since Octave started
+is_leap_year -- is the given year a leap year?
+* Other new functions:
+bug_report -- submit a bug report to the bug-octave mailing list
+toascii -- convert a string to a matrix of ASCII character codes
+octave_tmp_file -- generate a unique temporary file name
+undo_string_escapes -- replace special characters in a string by
+their backslash forms
+is_struct -- determine whether something is a structure data type
+feof   -- check EOF condition for a specified file
+ferror -- check error state for a specified file
+fread  -- read binary data from a file
+fwrite -- write binary data to a file
+file_in_path -- check to see if named file exists in given path
+kbhit  -- get a single character from the terminal
+axis   -- change plot ranges
+hist   -- plot histograms
+diary  -- save commands and output to a file
+type   -- show the definition of a function
+which  -- print the type of an identifier or the location of a
+function file
+isieee  -- Returns 1 if host uses IEEE floating point
+realmax -- Returns largest floating point number
+realmin -- Returns smallest floating point number
+gcd     -- greatest common divisor
+lcm     -- least common multiple
+null    -- orthonormal basis of the null space of a matrix
+orth    -- orthonormal basis of the range space of a matrix
+fft2    -- two-dimensional fast fourier transform
+ifft2   -- two-dimensional inverse fast fourier transform
+filter  -- digital filter
+fftfilt -- filter using fft
+fftconv -- convolve to vectors using fft
+sinc    -- returns sin(pi*x)/(pi*x)
+freqz   -- compute the frequency response of a filter
+* The meaning of nargin (== args.length ()) in built-in functions
+has been changed to match the meaning of nargin in user-defined
+functions.
+* Variable return lists.  Octave now has a real mechanism for
+handling functions that return an unspecified number of values,
+so it is no longer necessary to place an upper bound on the number
+of outputs that a function can produce.
+Here is an example of a function that uses the new syntax to
+produce n values:
+function [...] = foo (n)
+for i = 1:n
+vr_val (i * x);
+endfor
+endfunction
+* New keyword, all_va_args, that allows the entire list of va_args
+to be passed to another function.  For example, given the functions
+function f (...)
+while (nargin--)
+disp (va_arg ())
+endwhile
+endfunction
+function g (...)
+f ("begin", all_va_args, "end")
+endfunction
+the statement
+g (1, 2, 3)
+prints
+begin
+1
+2
+3
+end
+all_va_args may be used more than once, but can only be used
+within functions that take a variable number of arguments.
+* If given a second argument, svd now returns an economy-sized
+decomposition, eliminating the unecessary rows or columns of U or
+V.
+* The max and min functions correctly handle complex matrices in
+which some columns contain real values only.
+* The find function now handles 2 and 3 output arguments.
+* The qr function now allows computation of QR with pivoting.
+* hilb() is much faster for large matrices.
+* computer() is now a built-in function.
+* pinv() is now a built-in function.
+* The output from the history command now goes through the pager.
+* If a function is called without assigning the result, nargout is
+now correctly set to 0.
+* It is now possible to write functions that only set some return
+values.  For example, calling the function
+function [x, y, z] = f () x = 1; z = 2; endfunction
+as
+[a, b, c] = f ()
+produces:
+a = 1
+b = [](0x0)
+c = 2
+* The shell_cmd function has been renamed to system (the name
+shell_cmd remains for compatibility).  It now returns [output, status].
+* New built-in variable `OCTAVE_VERSION'.  Also a new function,
+version, for compatibility with Matlab.
+* New built-in variable `automatic_replot'.  If it is "true", Octave
+will automatically send a replot command to gnuplot each time the
+plot changes.  Since this is fairly inefficient, the default value
+is "false".
+* New built-in variable `whitespace_in_literal_matrix' allows some
+control over how Octave decides to convert spaces to commas in
+matrix expressions like `[m (1)]'.
+If the value of `whitespace_in_literal_matrix' is "ignore", Octave
+will never insert a comma or a semicolon in a literal matrix list.
+For example, the expression `[1 2]' will result in an error
+instead of being treated the same as `[1, 2]', and the expression
+[ 1, 2,
+3, 4 ]
+will result in the vector [1 2 3 4] instead of a matrix.
+If the value of `whitespace_in_literal_matrix' is "traditional",
+Octave will convert spaces to a comma between identifiers and `('.
+For example, given the matrix
+m = [3 2]
+the expression
+[m (1)]
+will be parsed as
+[m, (1)]
+and will result in
+[3 2 1]
+and the expression
+[ 1, 2,
+3, 4 ]
+will result in a matrix because the newline character is converted
+to a semicolon (row separator) even though there is a comma at the
+end of the first line (trailing commas or semicolons are ignored).
+This is apparently how Matlab behaves.
+Any other value for `whitespace_in_literal_matrix' results in
+behavior that is the same as traditional, except that Octave does
+not convert spaces to a comma between identifiers and `('.
+For example, the expression
+[m (1)]
+will produce 3.  This is the way Octave has always behaved.
+* Line numbers in error messages for functions defined in files and
+for script files now correspond to the file line number, not the
+number of lines after the function keyword appeared.
+* Octave now extracts help from script files.  The comments must
+come before any other statements in the file.
+* In function files, the first block of comments in the file will
+now be interpreted as the help text if it doesn't look like the
+Octave copyright notice.  Otherwise, Octave extracts the first set
+of comments after the function keyword.
+* The function clock is more accurate on systems that have the
+gettimeofday() function.
+* The standard output stream is now automatically flushed before
+reading from stdin with any of the *scanf() functions.
+* Expanded reference card.
+* The Octave distribution now includes a frequently asked questions
+file, with answers.  Better answers and more questions (with
+answers!) are welcome.
+* New option --verbose.  If Octave is invoked with --verbose and not
+--silent, a message is printed if an octaverc file is read while
+Octave is starting.
+* An improved configure script generated by Autoconf 2.0.
+* Lots of bug fixes.
+</pre>
+<h2>Summary of changes for version 1.0</h2>
+<pre>
+* C-style I/O functions now handle files referenced by name or by
+number more consistently.
+</pre>
+<h2>Summary of changes for version 0.83</h2>
+<pre>
+* Loading global symbols should work now.
+* Clearing the screen doesn't reprint the prompt unnecessarily.
+* The operations <complex scalar> OP <real matrix> for OP == +, -,
+*, or ./ no longer crash Octave.
+* More portability and configuration fixes.
+</pre>
+<h2>Summary of changes for version 0.82</h2>
+<pre>
+* Octave now comes with a reference card.
+* The manual has been improved, but more work remains to be done.
+* The atanh function now works for complex arguments.
+* The asin, acos, acosh, and atanh functions now work properly when
+given real-valued arguments that produce complex results.
+* SEEK_SET, SEEK_CUR, and SEEK_END are now constants.
+* The `using' qualifier now works with gplot and gsplot when the
+data to plot is coming directly from a file.
+* The strcmp function now works correctly for empty strings.
+* Eliminated bogus parse error for M-files that don't end with `end'
+or `endfunction'.
+* For empty matrices with one nonzero dimension, the +, -, .*, and
+./ operators now correctly preserve the dimension.
+* Octave no longer crashes if you type ^D at the beginning of a line
+in the middle of defining a loop or if statement.
+* On AIX systems, Back off on indexing DiagArray via Proxy class to
+avoid gcc (or possibly AIX assembler?) bug.
+* Various other bug and portability fixes.
+</pre>
+<h2>Summary of changes for version 0.81</h2>
+<pre>
+* Octave no longer dumps core if you try to define a function in
+your .octaverc file.
+* Fixed bug in Array class that resulted in bogus off-diagonal
+elements when computing eigenvalue and singular value
+decompositions.
+* Fixed bug that prevented lsode from working on the SPARCstation,
+at least with some versions of Sun's f77.  This bug was introduced
+in 0.80, when I changed LSODE to allow the user to abort the
+integration from within the RHS function.
+* Fixed bug that prevented global attribute of variables from being
+saved with save(), and another that prevented load() from working
+at all.
+</pre>
+<h2>Summary of changes for version 0.80</h2>
+<pre>
+* I have started working on a manual for the C++ classes.  At this
+point, it is little more than a list of function names.  If you
+would like to volunteer to help work on this, please contact
+bug-octave@bevo.che.wisc.edu.
+* The patterns accepted by the save and clear commands now work like
+file name globbing patterns instead of regular expressions.  I
+apologize for any inconvenience this change may cause, but file
+name globbing seems like a more reasonable style of pattern
+matching for this purpose.
+* It is now possible to specify tolerances and other optional inputs
+for dassl, fsolve, lsode, npsol, qpsol, and quad.  For each of
+these functions, there is a corresponding function X_options,
+which takes a keyword and value arguments.  If invoked without any
+arguments, the X_options functions print a list of possible
+keywords and current values.  For example,
+npsol_options ()
+prints a list of possible options with values, and
+npsol_options ("major print level", 10)
+sets the major print level to 10.
+The keyword match is not case sensitive, and the keywords may be
+abbreviated to the shortest unique match.  For example,
+npsol_options ("ma p", 10)
+is equivalent to the statement shown above.
+* The new built-in variable save_precision can be used to set the
+number of digits preserved by the ASCII save command.
+* Assignment of [] now works in most cases to allow you to delete
+rows or columns of matrices and vectors.  For example, given a
+4x5 matrix A, the assignment
+A (3, :) = []
+deletes the third row of A, and the assignment
+A (:, 1:2:5) = []
+deletes the first, third, and fifth columns.
+* Variable argument lists.  Octave now has a real mechanism for
+handling functions that take an unspecified number of arguments,
+so it is no longer necessary to place an upper bound on the number
+of optional arguments that a function can accept.
+Here is an example of a function that uses the new syntax to print
+a header followed by an unspecified number of values:
+function foo (heading, ...)
+disp (heading);
+va_start ();
+while (--nargin)
+disp (va_arg ());
+endwhile
+endfunction
+Note that the argument list must contain at least one named
+argument (this restriction may eventually be removed), and the
+ellipsis must appear as the last element of the argument list.
+Calling va_start() positions an internal pointer to the first
+unnamed argument and allows you to cycle through the arguments
+more than once.  It is not necessary to call va_start() if you
+do not plan to cycle through the arguments more than once.
+* Recursive functions should work now.
+* The environment variable OCTAVE_PATH is now handled in the same
+way as TeX handles TEXINPUTS.  If the path starts with `:', the
+standard path is prepended to the value obtained from the
+environment.  If it ends with `:' the standard path is appended to
+the value obtained from the environment.
+* New functions, from Kurt Hornik (hornik@neuro.tuwien.ac.at) and
+the Department of Probability Theory and Statistics TU Wien,
+Austria:
+corrcoef    -- corrcoef (X, Y) is the correlation between the i-th
+variable in X and the j-th variable in Y
+corrcoef (X) is corrcoef (X, X)
+cov         -- cov (X, Y) is the covariance between the i-th
+variable in X and the j-th variable in Y
+cov (X) is cov (X, X)
+gls         -- generalized least squares estimation
+kurtosis    -- kurtosis(x) = N^(-1) std(x)^(-4) SUM_i (x(i)-mean(x))^4 - 3
+If x is a matrix, return the row vector containing
+the kurtosis of each column
+mahalanobis -- returns Mahalanobis' D-square distance between the
+multivariate samples X and Y, which must have the
+same number of components (columns), but may have
+a different number of observations (rows)
+ols         -- ordinary least squares estimation
+pinv        -- returns the pseudoinverse of X; singular values
+less than tol are ignored
+skewness    -- skewness (x) = N^(-1) std(x)^(-3) SUM_i (x(i)-mean(x))^3
+if x is a matrix, return the row vector containing
+the skewness of each column
+* Errors in user-supplied functions called from dassl, fsolve,
+lsode, npsol, and quad are handled more gracefully.
+* Programming errors in the use of the C++ classes within Octave
+should no longer cause Octave to abort.  Instead, Octave's error
+handler function is called and execution continues as best as is
+possible.  This should result in eventually returning control to
+the top-level Octave prompt.  (It would be nice to have a real
+exception handling mechanism...)
+* A number of memory leaks have been eliminated.  Thanks to
+Fong Kin Fui <fui@ee.nus.sg> for reporting them.
+* The C++ matrix classes are now derived from a generic
+template-based array class.
+* The readline function operate-and-get-next (from bash) is now
+available and bound to C-O by default.
+* Octave now uses the version of readline currently distributed with
+bash-1.13.  On some systems, interactive invocations of Octave
+will now blink the cursor to show matching parens.
+* By default, include files are now installed in
+$prefix/include/octave instead of $prefix/include.
+* Octave now uses a config.h file instead of putting all defines on
+the compiler command line.
+</pre>
+<h2>Summary of changes for version 0.79</h2>
+<pre>
+* New control systems functions:
+dgram -- Returns the discrete controllability and observability gramian.
+dlqr  -- Discrete linear quadratic regulator design.
+dlqe  -- Discrete linear quadratic estimator (Kalman Filter) design.
+c2d   -- Convert continuous system description to discrete time
+description assuming zero-order hold and given sample time.
+* The max (min) functions can now return the index of the max (min)
+value as a second return value.
+</pre>
+<h2>Summary of changes for version 0.78</h2>
+<pre>
+* Octave's handling of global variables has been completely
+rewritten.  To access global variables inside a function, you must
+now declare them to be global within the function body.  Likewise,
+if you do not declare a variable as global at the command line,
+you will not have access to it within a function, even if it is
+declared global there.  For example, given the function
+function f ()
+global x = 1;
+y = 2;
+endfunction
+the global variable `x' is not visible at the top level until the
+command
+octave:13> global x
+has been evaluated, and the variable `y' remains local to the
+function f() even if it is declared global at the top level.
+Clearing a global variable at the top level will remove its global
+scope and leave it undefined.  For example,
+octave:1> function f ()   # Define a function that accesses
+>  global x;              #   the global variable `x'.
+>  x
+> endfunction
+octave:2> global x = 1    # Give the variable `x' a value.
+octave:3> f ()            # Evaluating the function accesses the
+x = 1                     #   global `x'.
+octave:4> clear x         # Remove `x' from global scope, clear value.
+octave:5> x = 2           # Define new local `x' at the top level
+x = 2
+octave:6> f               # The global `x' is no longer defined.
+error: `x' undefined near line 1 column 25
+error: evaluating expression near line 1, column 25
+error: called from `f'
+octave:7> x               # But the local one is.
+x = 2
+* The new function, `is_global (string)' returns 1 if the variable
+named by string is globally visible.  Otherwise, returns 0.
+* The implementation of `who' has changed.  It now accepts the
+following options:
+-b -builtins   -- display info for built-in variables and functions
+-f -functions  -- display info for currently compiled functions
+-v -variables  -- display info for user variables
+-l -long       -- display long info
+The long output looks like this:
+octave:5> who -l
+*** currently compiled functions:
+prot  type               rows   cols  name
+====  ====               ====   ====  ====
+wd   user function         -      -  f
+*** local user variables:
+prot  type               rows   cols  name
+====  ====               ====   ====  ====
+wd   real scalar           1      1  y
+*** globally visible user variables:
+prot  type               rows   cols  name
+====  ====               ====   ====  ====
+wd   complex matrix       13     13  x
+where the first character of the `protection' field is `w' if the
+symbol can be redefined, and `-' if it has read-only access.  The
+second character may be `d' if the symbol can be deleted, or `-'
+if the symbol cannot be cleared.
+* The new built-in variable ignore_function_time_stamp can be used
+to prevent Octave from calling stat() each time it looks up
+functions defined in M-files.  If set to "system", Octave will not
+automatically recompile M-files in subdirectories of
+$OCTAVE_HOME/lib/VERSION if they have changed since they were last
+compiled, but will recompile other M-files in the LOADPATH if they
+change.  If set to "all", Octave will not recompile any M-files
+unless their definitions are removed with clear.  For any other
+value of ignore_function_time_stamp, Octave will always check to
+see if functions defined in M-files need to recompiled.  The
+default value of ignore_function_time_stamp is "system".
+* The new built-in variable EDITOR can be used to specify the editor
+for the edit_history command.  It is set to the value of the
+environment variable EDITOR, or `vi' if EDITOR is not set, or is
+empty.
+* There is a new built-in variable, INFO_FILE, which is used as the
+location of the info file.  Its initial value is
+$OCTAVE_HOME/info/octave.info, so `help -i' should now work
+provided that OCTAVE_HOME is set correctly, even if Octave is
+installed in a directory different from that specified at compile
+time.
+* There is a new command line option, --info-file FILE, that may be
+used to set Octave's idea of the location of the info file.  It
+will override any value of OCTAVE_INFO_FILE found in the
+environment, but not any INFO_FILE="filename" commands found in
+the system or user startup files.
+* Octave's Info reader will now recognize gzipped files that have
+names ending in `.gz'.
+* The save command now accepts regular expressions as arguments.
+Note that these patterns are regular expressions, and do not work
+like filename globbing.  For example, given the variables `a',
+`aa', and `a1', the command `save a*' saves `a' and `aa' but not
+`a1'.  To match all variables beginning with `a', you must use an
+expression like `a.*' (match all sequences beginning with `a'
+followed by zero or more characters).
+* Line and column information is included in more error messages.
+</pre>
+<h2>Summary of changes for version 0.77</h2>
+<pre>
+* Improved help.  The command `help -i topic' now uses the GNU Info
+browser to display help for the given topic directly from the
+Texinfo documenation.
+* New function: chol -- Cholesky factorization.
+</pre>
+<h2>Summary of changes for version 0.76</h2>
+<pre>
+* Better run-time error messages.  Many now include line and column
+information indicating where the error occurred.  Octave will also
+print a traceback for errors occurring inside functions. If you
+find error messages that could use improvement, or errors that
+Octave fails to catch, please send a bug report to
+bug-octave@bevo.che.wisc.edu.
+* If gplot (or gsplot) is given a string to plot, and the string
+does not name a file, Octave will pass the string along to gnuplot
+directly.  This allows commands like
+gplot "sin (x)" w l, data w p
+to work (assuming that data is a variable containing a matrix of
+values).
+* Long options (--help, --version, etc.) are supported.
+</pre>
+<h2>Summary of changes for version 0.75</h2>
+<pre>
+* The documentation is much more complete, but still could use a lot
+of work.
+* The history function now prints line numbers by default.  The
+command `history -q' will  omit them.
+* The clear function now accepts regular expressions.
+* If gplot (or gsplot) is given a string to plot, and the string
+names a file, Octave attempts to plot the contents of the file.
+* New functions:
+history:
+run_history  -- run commands from the history list.
+edit_history -- edit commands from the history list with your
+favorite editor.
+linear algebra:
+balance         -- Balancing for algebraic and generalized
+eigenvalue problems.
+givens          -- Givens rotation.
+is_square       -- Check to see if a matrix is square.
+qzhess          -- QZ decomposition of the matrix pencil (a - lambda b).
+qzval           -- Generalized eigenvalues for real matrices.
+syl             -- Sylvester equation solver.
+control systems:
+is_symmetric    -- Check to see if a matrix is symmetric.
+abcddim         -- Check dimensions of linear dynamic system [A,B,C,D].
+is_controllable -- Check to see if [A,B,C,D] is controllable.
+is_observable   -- Check to see if [A,B,C,D] is observable.
+are             -- Solve algebraic Ricatti equation.
+dare            -- Solve discrete-time algebraic Ricatti equation.
+lqe             -- Kalman filter design for continuous linear system.
+lqr             -- Linear Quadratic Regulator design.
+lyap            -- Solve Lyapunov equation.
+dlyap           -- Solve discrete Lyapunov equation.
+tzero           -- Compute the transmission zeros of [A,B,C,D].
+</pre>
+<h2>Summary of changes for version 0.74</h2>
+<pre>
+* Formal parameters to functions are now always considered to be
+local variables, so things like
+global x = 0
+global y = 0
+function y = f (x) x = 1; y = x; end
+f (x)
+result in the function returning 1, with the global values of x
+and y unchanged.
+* Multiple assignment expressions are now allowed to take indices,
+so things like
+octave:13> [a([1,2],[3,4]), b([5,6],[7,8])] = lu ([1,2;3,4])
+will work correctly.
+</pre>
+<h2>Summary of changes for version 0.73</h2>
+<pre>
+* Saving and loading global variables works correctly now.
+* The save command no longer saves built-in variables.
+* Global variables are more reliable.
+* Matrices may now have one or both dimensions zero, so that
+operations on empty matrices are now handled more consistently.
+By default, dimensions of the empty matrix are now printed along
+with the empty matrix symbol, `[]'.  For example:
+octave:13> zeros (3, 0)
+ans =
+[](3x0)
+The new variable `print_empty_dimensions' controls this behavior.
+See also Carl de Boor, An Empty Exercise, SIGNUM, Volume 25,
+pages 2--6, 1990, or C. N. Nett and W. M. Haddad, A
+System-Theoretic Appropriate Realization of the Empty Matrix
+Concept, IEEE Transactions on Automatic Control, Volume 38,
+Number 5, May 1993.
+* The right and left division operators `/' and `\' will now find a
+minimum norm solution if the system is not square, or if the
+coefficient matrix is singular.
+* New functions:
+hess   -- Hessenberg decomposition
+schur  -- Ordered Schur factorization
+perror -- print error messages corresponding to error codes
+returned from the functions fsolve, npsol, and qpsol
+(with others to possibly be added later).
+* Octave now prints a warning if it finds anything other than
+whitespace or comments after the final `end' or `endfunction'
+statement.
+* The bodies of functions, and the for, while, and if commands are
+now allowed to be empty.
+* Support for Gill and Murray's QPSOL has been added.  Like NPSOL,
+QPSOL is not freely redistributable either, so you must obtain
+your own copy to be able to use this feature.  More information
+about where to find QPSOL and NPSOL are in the file README.NLP.
+</pre>
+<h2>Summary of changes for version 0.72</h2>
+<pre>
+* For numeric output, columns are now lined up on the decimal point.
+(This requires libg++-2.3.1 or later to work correctly).
+* If octave is running interactively and the output intended for the
+screen is longer than one page and a pager is available, it is
+sent to the pager through a pipe.  You may specify the program to
+use as the pager by setting the variable PAGER.  PAGER may also
+specify a command pipeline.
+* Spaces are not always significant inside square brackets now, so
+commands like
+[ linspace (1, 2) ]
+will work.  However, some possible sources of confusion remain
+because Octave tries (possibly too hard) to determine exactly what
+operation is intended from the context surrounding an operator.
+For example:
+-- In the command
+[ 1 - 1 ]
+the `-' is treated as a binary operator and the result is the
+scalar 0, but in the command
+[ 1 -1 ]
+the `-' is treated as a unary operator and the result is the
+vector [ 1 -1 ].
+-- In the command
+a = 1; [ 1 a' ]
+the single quote character `'' is treated as a transpose operator
+and the result is the vector [ 1 1 ], but in the command
+a = 1; [ 1 a ' ]
+an error message indicating an unterminated string constant is
+printed.
+* Assignments are just expressions now, so they are valid anywhere
+other expressions are.  This means that things like
+if (a = n < m) ... endif
+are valid.  This is parsed as:  compare `n < m', assign the result
+to the variable `a', and use it as the test expression in the if
+statement.
+To help avoid errors where `=' has been used but `==' was
+intended, Octave issues a warning suggesting parenthesis around
+assignments used as truth values.  You can suppress this warning
+by adding parenthesis, or by setting the value of the new built-in
+variable `warn_assign_as_truth_value' to 'false' (the default
+value is 'true').
+This is also true for multiple assignments, so expressions like
+[a, b, c] = [u, s, v] = expression
+are now possible.  If the expression is a function, nargout is set
+to the number of arguments for the right-most assignment.  The
+other assignments need not contain the same number of elements.
+Extra left hand side variables in an assignment become undefined.
+* The default line style for plots is now `lines' instead of
+`points'.  To change it, use the `set data style STYLE' command.
+* New file handling and I/O functions:
+fopen    -- open a file for reading or writing
+fclose   -- close a file
+fflush   -- flush output to a file
+fgets    -- read characters from a file
+frewind  -- set file position to the beginning of a file
+fseek    -- set file position
+ftell    -- tell file position
+freport  -- print a report for all open files
+fscanf   -- read from a file
+sscanf   -- read from a string
+scanf    -- read from the standard input
+* New built-in variables for file and I/O functions:
+stdin    -- file number corresponding to the standard input stream.
+stdout   -- file number corresponding to the standard output stream.
+stderr   -- file number corresponding to the standard error stream.
+The following may be used as the final (optional) argument for
+fseek:
+SEEK_SET -- set position relative to the beginning of the file.
+SEEK_CUR -- set position relative to the current position.
+SEEK_END -- set position relative to the end of the file.
+* New function: setstr -- convert vectors or scalars to strings
+(doesn't work for matrices yet).
+* If possible, computer now prints the system type instead of
+always printing `Hi Dave, I'm a HAL-9000'.
+* Octave now properly saves and restores its internal state
+correctly in more places.  Interrupting Octave while it is
+executing a script file no longer causes it to exit.
+* Octave now does tilde expansion on each element of the LOADPATH.
+* A number of memory leaks have been plugged.
+* Dependencies for C++ source files are now generated automatically
+by g++.
+* There is a new command line option, -p PATH, that may be used to
+set Octave's loadpath from the command line.  It will override any
+value of OCTAVE_PATH found in the environment, but not any
+LOADPATH="path" commands found in the system or user startup files.
+* It is now possible to override Octave's default idea of the
+location of the system-wide startup file (usually stored in
+$(prefix)/lib/octave/octaverc) using the environment variable
+OCTAVE_HOME.  If OCTAVE_HOME has a value, Octave will look for
+octaverc and its M-files in the directory $OCTAVE_HOME/lib/octave.
+This allows people who are using binary distributions (as is
+common with systems like Linux) to install the real octave binary
+in any directory (using a name like octave.bin) and then install
+a simple script like this
+#!/bin/sh
+OCTAVE_HOME=/foo/bar/baz
+export OCTAVE_HOME
+exec octave.bin
+to be invoked as octave.
+</pre>
+<h2>Summary of changes for version 0.71</h2>
+<pre>
+* Much improved plotting facility.  With this release, Octave does
+not require a specially modified version of gnuplot, so gnuplot
+sources are no longer distributed with Octave.  For a more
+detailed description of the new plotting features, see the file
+PLOTTING.
+* New plotting commands:
+plot            -- 2D plots
+semilogx        -- 2D semilog plot with logscale on the x axis
+semilogy        -- 2D semilog plot with logscale on the y axis
+loglog          -- 2D log-log plot
+mesh            -- 3D mesh plot
+meshdom         -- create matrices for 3D plotting from two vectors
+contour         -- contour plots of 3D data
+bar             -- create bar graphs
+stairs          -- create stairstep plots
+polar           -- 2D plots from theta-R data
+grid            -- turn plot grid lines on or off
+xlabel, ylabel  -- place labels on the x and y axes of 2D plots
+sombrero        -- demonstrate 3D plotting
+gplot           -- 2D plot command with gnuplot-like syntax
+gsplot          -- 3D plot command with gnuplot-like syntax
+set             -- set plot options with gnuplot syntax
+show            -- show plot options with gnuplot syntax
+closeplot       -- close stream to gnuplot process
+purge_tmp_files -- delete temporary files created by plot command
+* Other new commands:
+ls, dir         -- print a directory listing
+shell_cmd       -- execute shell commands
+keyboard        -- get input from keyboard, useful for debugging
+menu            -- display a menu of options and ask for input
+fft             -- fast fourier transform
+ifft            -- inverse fast fourier transform
+* Strings may be enclosed in either single or double quote
+characters.  Double quote characters are not special within single
+quote strings, and single quotes are not special within double
+quote strings.
+* Command name completion now works for M-file names too.
+* Better help and usage messages for many functions.
+* Help is now available for functions defined in M-files.  The first
+block of comments is taken as the text of the help message.
+* Numerous changes in preparation to support dynamic loading of
+object files with dld.
+* Bug fixes to make solving DAEs with dassl actually work.
+* The command `save file' now saves all variables in the named file.
+* If do_fortran_indexing is 'true', indexing a scalar with
+[1,1,1,...] (n times) replicates its value n times.  The
+orientation of the resulting vector depends on the value of
+prefer_column_vectors.
+* Things like [[1,2][3,4]] no longer cause core dumps, and invalid
+input like [1,2;3,4,[5,6]] now produces a diagnositic message.
+* The cd, save, and load commands now do tilde expansion.
+* It's now possible to clear global variables and functions by name.
+* Use of clear inside functions is now a parse error.
+</pre>
+<h2>Summary of changes for version 0.70</h2>
+<pre>
+* Better parse error diagnostics.  For interactive input, you get
+messages like
+octave:1> a = 3 + * 4;
+parse error:
+a = 3 + * 4;
+^
+and for script files, the message includes the file name and input
+line number:
+octave:1> foo
+parse error near line 4 of file foo.m:
+a = 3 + * 4;
+^
+* New built-in variable PS2 which is used as the secondary prompt.
+The default value is '> '.
+* New file, octave-mode.el, for editing Octave code with GNU Emacs.
+This is a modified version of Matthew R. Wette's matlab-mode.el.
+* Better support for missing math functions.
+* User preferences are now cached in a global struct so we don't
+have to do a symbol table lookup each time we need to know what
+they are.  This should mean slightly improved performance for
+evaluating expressions.
+</pre>
+<h2>Summary of changes for version 0.69</h2>
+<pre>
+* Multiple assignments are now possible, so statements like
+a = b = c = 3;
+a = b = c = [1,2;3,4];
+or
+c = (a = (b = 2) * 3 + 4) * 5
+are legal, as are things that have even more bizarre effects, like
+a(4:6,4:6) = b(2:3,2:3) = [1,2;3,4];
+(try it).
+* Improved parsing of strings (but they still don't work as matrix
+elements).
+* An M-file may now either define a function or be a list of
+commands to execute.
+* Better detection and conditional compilation of IEEE functions
+isinf, finite, and isnan.
+* Replacements for acosh, asinh, atanh, and gamma from the BSD math
+library for those systems that don't have them.
+</pre>
+<h2>Summary of changes for version 0.68</h2>
+<pre>
+* New functions:
+eval  -- evaluate a string as a sequence of Octave commands.
+input -- print a prompt and get user input.
+</pre>
+<h2>Summary of changes for version 0.67</h2>
+<pre>
+* New functions:
+find -- return the indices of nonzero elements.
+* Zero-one style indexing now works.  For example,
+a = [1,2,3,4];
+b = a([1,0,0,1])
+sets b to the first and fourth elememnts of a.
+Zero-one style indexing also works for indexing the left hand side
+of an assignment.  For example,
+a = rand (1,2;3,4);
+a([0,1],:) = [-1,-2]
+sets the second row of a to [-1 -2]
+The behavior for the ambiguous case
+a = [1,2,3,4];
+b = a([1,1,1,1]);
+is controlled by the new global variable `prefer_zero_one_indexing'.
+If this variable is equal to 'true', b will be set to [1 2 3 4].
+If it is false, b will be set to [1 1 1 1].  The default value is
+'false'.
+* Using the new global variable `propagate_empty_matrices', it is
+possible to have unary andy binary operations on empty matrices
+return an empty matrix.  The default value of this variable is
+'warn', so that empty matrices are propagated but you get a
+warning.  Some functions, like eig and svd have also been changed
+to handle this.
+* Empty matrices can be used in conditionals, but they always
+evaluate to `false'.  With propagate_empty_matrices = 'true', both
+of the following expressions print 0:
+if  [], 1, else 0, end
+if ~[], 1, else 0, end
+* Octave no longer converts input like `3.2 i' or `3 I' to complex
+constants directly because that causes problems inside square
+brackets, where spaces are important.  This abbreviated notation
+*does* work if there isn't a space between the number and the i,
+I, j, or J.
+</pre>
+<h2>Summary of changes for version 0.66</h2>
+<pre>
+* Logical unary not operator (~ or !) now works for complex.
+* Left division works.
+* Right and left element by element division should work correctly
+now.
+* Numbers like .3e+2 are no longer errors.
+* Indexing a matrix with a complex value doesn't cause a core dump.
+* The min and max functions should work correctly for two arguments.
+* Improved (I hope!) configuration checks.
+* Octave is now installed as octave-M.N, where M and N are version
+numbers, and octave is a link to that file.  This makes it
+possible to have more than one version of the interpreter installed.
+</pre>
+<h2>Summary of changes for version 0.63</h2>
+<pre>
+* The reshape function works again.
+* Octave now converts input like `3.2i' or `3 I' or `2.3e5 j' to be
+complex constants directly, rather than requiring an expression
+like `3.3 * i' to be evaluated.
+</pre>
+<h2>Summary of changes for version 0.61</h2>
+<pre>
+* Octave has been successfully compiled using gcc 2.3.3 and libg++ 2.3.
+on a 486 system running Linux.
+* The win_texas_lotto function is now called texas_lotto (it's a
+script file, and win_texas_lotto.m is too long for some Linux and
+System V systems).
+</pre>
+<h2>Summary of changes for version 0.57</h2>
+<pre>
+* The C-like formatted print functions printf, fprintf, and sprintf
+finally work.
+</pre>
+<h2>Summary of changes for version 0.56</h2>
+<pre>
+* By default, octave prints a short disclaimer when it starts.
+(You can suppress it by invoking octave with -q).
+* You can keep octave from reading your ~/.octaverc and .octaverc
+files by invoking it with -f.
+* When returning two values, eig now returns [v, d] instead of
+[lambda, v], where d is a diagonal matrix made from lambda.
+* The win_texas_lotto function now produces a sorted list.
+* New functions:
+expm -- matrix exponential.
+logm -- matrix logarithm.
+</pre>
+<h2>Summary of changes for version 0.55</h2>
+<pre>
+* The following (C-style) backslash escape sequences work in quoted
+strings (useful(?) with printf()):
+\a  bell         \r  carriage return
+\b  backspace    \t  horizontal tab
+\f  formfeed     \v  vertical tab
+\n  newline      \\  backslash
+* Use of `...' at the end of a line will allow a statement to
+continue over more than one line.
+* The names `inf' and `nan' are now aliases for `Inf' and `NaN',
+respectively.
+* New functions:
+casesen -- print a warning if the luser tries to turn off case
+sensitivity.
+median  -- find median value.
+norm    -- compute the norm of a matrix.
+sort    -- sort columns.
+* New variable, `silent_functions'.  If silent_functions == 'true',
+the results of expressions are not printed even if they are not
+followed by a semicolon.  The disp() and printf() functions still
+result in output.  The default value for this variable is 'false'.
+* New variable `return_last_value_computed'.  If it is 'true',
+functions defined in script files return the last value computed
+if a return value has not been explicitly declared.  The default
+value for this variable is 'false'.
+</pre>
+<h2>Summary of changes for version 0.52</h2>
+<pre>
+* Name completion works for function and variable names currently in
+the symbol tables.  Coming soon: completion for names of functions
+defined in script files but not yet compiled.
+* The initial value of do_fortran_indexing is now false, and the
+initial value of prefer_column_vectors is now true.  Swap the
+values of these variables if you want behavior that is more like
+Matlab.
+* All script files check the number of input arguments before doing
+much real work.
+* The identifiers `i' and `j' are now also names for sqrt(-1).
+These symbols may be used for other purposes, but their original
+definition will reappear if they are cleared.
+* The symbol tables are now implemented with hash tables for faster
+searching.
+* A small amount of help is now available for most built-in
+operators, keywords and functions.  Coming soon: help for script
+files.
+* Without any arguments, the help command now lists all known
+built-in operators, keywords and functions.
+* Generic parse errors are now signalled by `Eh, what's up doc?',
+which is closer to what Bugs actually says.
+* The who command now only prints variable names by default.
+Use the -fcn (or -fcns, or -functions) switch to print the names of
+built-in or currently compiled functions.
+</pre>
+<h2>Summary of changes for version 0.51</h2>
+<pre>
+* Major overhaul of array indexing.
+* The colloc function actually works now.
+</pre>
+<h2>Summary of changes for version 0.50</h2>
+<pre>
+* The lsode and dassl functions now return the states only,
+instead of the time and the states, so you must keep track of
+the corresponding times (this is easy though, because you have
+to specify a vector of desired output times anyway).
+* Solution of NLPs with NPSOL now works on the SPARC.
+* New keywords `endif', `endfor', `endfunction', `endif', and
+`endwhile', which allow for better diagnostics.  The `end' keyword
+is still recognized.  All script files have been changed to use
+these new keywords in place of `end'.
+* It is now possible to uninstall Octave by doing a `make uninstall'
+in the top level directory.
+* The Makefiles are much closer to conforming with GNU coding standards.
+* New functions:
+win_texas_lotto  -- produce six unique random numbers between 1 and 50.
+quad             -- numerical integration.
+lu               -- LU factorization
+qr               -- QR factorization
+dassl            -- Solution of DAEs using DASSL.
+* New files:
+THANKS -- A list of people and organazations who have supported
+the development of Octave.
+NEWS   -- This file, listing recent changes.
+* Help is now available at the gnuplot prompt.
+</pre>
+</body>
+</html>

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