Summary of important user-visible changes for version 7 (yyyy-mm-dd):
----------------------------------------------------------------------

### General improvements

- Many functions in Octave can be called in a command form---no
parentheses for invocation and no return argument assignment---or in a
functional form---parentheses and '=' for assignment of return values.

    Command Form Example

    `mkdir new_directory`

    Function Form Example

    `status = mkdir ("new_directory")`

    Octave now handles errors that occur in a consistent manner.  If
    called in command form and there is a failure, an error is thrown
    and a message printed.  If called in functional form, no error or
    message is printed and the failure is communicated to the programmer
    via the output status variable.

    The following list of functions have been modified.

    * `copyfile`
    * `fcntl`
    * `fileattrib`
    * `kill`
    * `link`
    * `mkfifo`
    * `movefile`
    * `rename`
    * `rmdir`
    * `symlink`
    * `unlink`

### Graphics backend

- Support for Qt4 for graphics and the GUI has been removed.

### Matlab compatibility

- Calling a user-defined function with too many inputs or outputs is now
an error.  The interpreter makes this check automatically.  If a
function uses varargin then the check is skipped for function inputs,
and if a function uses varargout then the check is skipped for function
outputs.

- The function `griddata` now implements the "v4" Biharmonic Spline
Interpolation method.  In adddition, the function now accepts 3-D inputs
by passing the data to `griddata3`.

- Coordinate transformation functions `cart2sph`, `sph2cart`,
`cart2pol`, and `pol2cart` now accept either row or column vectors for
coordinate inputs.  A single coordinate matrix with one variable per
column can still be used as function input, but a single output variable
will now contain just the first output coordinate, and will no longer
return the full output coordinate matrix.  Output size matches the size
of input vectors, or in the case of an input matrix will be column
vectors with rows corresponding to the input coordinate matrix.

- The function `dec2bin` and `dec2hex` now support negative numbers.

- Binary and hexadecimal constants like `0b101` and `0xDEADBEEF` now
create integers (unsigned by default) with sizes determined from the
number of digits present.  For example, `0xff` creates a `uint8` value
and `0xDEADBEEF` creates a `uint64` value.  You may also use a suffix of
the form `s8`, `s16`, `s32`, `s64`, `u8`, `u16`, `u32`, or `u64` to
explicitly specify the data type to use (`u` or `s` to indicate signed
or unsigned and the number to indicate the integer size).

Binary constants are limited to 64 binary digits and hexadecimal
constants are limited to 16 hexadecimal digits with no automatic
rounding or conversion to floating point values.  Note that this may
cause problems in existing code.  For example, an expression like
`[0x1; 0x100; 0x10000]` will be uint8 (because of the rules of
concatenating integers of different sizes) with the larger values
truncated (because of the saturation semantics of integer values).  To
avoid these kinds of problems either: 1) declare the first integer to be
of the desired size such as `[0x1u32; 0x100; 0x10000]`, or 2) pad
constants in array expressions with leading zeros so that they use the
same number of digits for each value such as
`[0x00_00_01; 0x00_01_00; 0x01_00_00]`.

- The function `importdata` now produces more compatible results when
the file contains a 2-D text matrix.

- `uicontrol` objects now fully implement the "Off" and "Inactive"
values of the "Enable" property.  When the value is "Off", no
interaction with the object occurs and the `uicontrol` changes color
(typically to gray) to indicate it is disabled.  When the value is
"Inactive", the object appears normally (no change in color), but it is
not possible to change the value of the object (such as modifying text
in an `Edit` box or clicking on a `RadioButton`).

- The functions `scatter` and `scatter3` now return a handle to a
scatter graphics object.  For compatibility, they return an `hggroup` of
patch graphics objects when the "gnuplot" graphics toolkit is used.  In
previous versions of Octave, these functions returned a hg group of
patch graphics objects for all graphics toolkits.

- The function `saveas` now defaults to saving in Octave figure format
(.ofig) rather than PDF (.pdf).

- The additional property "contextmenu" has been added to all graphics
objects.  It is equivalent to the previously used "uicontextmenu"
property which is hidden now.

- A new warning ID (Octave:unimplemented-matlab-functionality) has been
added which prints a warning when Octave's parser recognizes valid
Matlab code, but for which Octave does not yet implement the
functionality.  By default, this warning is enabled.

- Additional properties have been added to the `axes` graphics object:
    * "alphamap" (not yet implemented)
    * "alphascale" (not yet implemented)
    * "colorscale" (not yet implemented)
    * "fontsizemode" (not yet implemented)
    * "innerposition" (equivalent to "position")
    * "interactions" (not yet implemented)
    * "layout" (not yet implemented)
    * "legend" (not yet implemented)
    * "nextseriesindex" (read-only, used by `scatter` graphics objects)
    * "positionconstraint" (replacement for "activepositionproperty"
      which is now a hidden property.  No plans for removal.)
    * "toolbar" (not yet implemented)
    * "xaxis" (not yet implemented)
    * "yaxis" (not yet implemented)
    * "zaxis" (not yet implemented)

### Alphabetical list of new functions added in Octave 7

* `getpixelposition`
* `endsWith`
* `listfonts`
* `memory`
* `rng`
* `startsWith`
* `streamribbon`

### Deprecated functions and properties

The following functions and properties have been deprecated in Octave 7
and will be removed from Octave 9 (or whatever version is the second
major release after 7):

- Functions

  Function               | Replacement
  -----------------------|------------------
                         |

- Properties

  Object           | Property      | Value
  -----------------|---------------|------------
                   |               |

### Removed functions and properties

The following functions and properties were deprecated in Octave 5
and have been removed from Octave 7.

- Functions

  Function                 | Replacement
  -------------------------|------------------
  `output_max_field_width` | `output_precision`
  `is_keyword`             | `iskeyword`

- Properties

  Object           | Property      | Value
  -----------------|---------------|------------
  `text`           | `fontangle`   | `"oblique"`
  `uibuttongroup`  | `fontangle`   | `"oblique"`
  `uicontrol`      | `fontangle`   | `"oblique"`
  `uipanel`        | `fontangle`   | `"oblique"`
  `uitable`        | `fontangle`   | `"oblique"`

### Old release news

- [Octave 6.x](etc/NEWS.6)
- [Octave 5.x](etc/NEWS.5)
- [Octave 4.x](etc/NEWS.4)
- [Octave 3.x](etc/NEWS.3)
- [Octave 2.x](etc/NEWS.2)
- [Octave 1.x](etc/NEWS.1)