ExperimentalStuff

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ExperimentalStuff -- Experimental stuff in this release of Psychtoolbox:

The following components of Psychtoolbox have to be considered
experimental features, even if they are part of a "stable"
release or an official Psychtoolbox-x.y.z version.

If you use any of these features then you have to be aware that
they may be incomplete in their implementation, have known issues,
or their design and programming interface is subject to change
in the future, so it may require you to adapt your experiment
code to the changing interface when upgrading to a future release
of Psychtoolbox.


GETCHAR: (Allen Ingling, Christopher Broussard, Mario Kleiner)

The GetChar implementation in this release is implemented in the
Java programming language. It is therefore dependent on Matlab's
built-in Java support. GetChar is supposed to work with all
Java virtual machines of version 1.4.2 or later. As such it should
work on all Matlab versions on MacOS-X 10.3.9 and later. On Microsoft
Windows and GNU/Linux it is supposed to work with Matlab 7.0.0 and
later, but not on earlier versions of Matlab. GetChar has been tested
on Matlab 7.1 for M$-Windows and with Matlab on OS-X 10.3.9 and 10.4.7.

On OS-X, GetChar will only work in Java mode, i.e. it won't work in
matlab -nojvm mode. On Microsoft Windows, GetChar will also work in
matlab -nojvm mode by use of a C implementation of GetChar, but it
will not return any additional information (e.g., timestamps) then.
GetChar doesn't work well (or at all) on MS-Windows Vista or Windows-7.
It also has various limitations when used with GNU/Octave.

The time stamps for key presses returned by GetChar are known to be
not very accurate and not perfectly consistent with timestamps returned
by KbCheck, KbWait, GetSecs and other PTB functions. For accurate timing
do not rely on GetChar. It is recommended to run "TestGetChar" before
first use of GetChar to verify its proper working and to get a feeling
for the (in)accuracy of its timestamps. Read "help GetChar" and in case
of trouble, read "help PsychJavaTrouble".

We generally recommend using KbCheck and KbWait instead of GetChar if
possible, as these functions are well tested and known to be robust,
whereas GetChar is known to be one of the most fragile and troublesome
functions in Psychtoolbox. GetEchoNumber, GetEchoString and GetKbChar are
good alternatives to use of GetChar for many common purposes.

iViewXToolbox: (Frans Cornelissen)

The iViewXToolbox should allow to control iView Gazetrackers from Matlab.
The current version is a very early prototype, most likely not yet functional,
just included for backup purpose.

PSYCHSOUND: (Mario Kleiner)

PsychSound is obsolete! It only worked on OS/X PowerPC and has been
superseded by PsychPortAudio(). It is left in the distribution for
backwards compatibility.

PsychSound was supposed to be a well working replacement for the Snd
function in the far future. As of now, it only works on MacOS-X for
PowerPC computers and it is only useable for capture of sound input,
not for sound playback. Sound capture works well, but the interface
is subject to change in the future, so code that makes use of PsychSound
may need to be slightly rewritten in the future.


MOGL OpenGL for Matlab support: (Richard F. Murray, Mario Kleiner)

The OpenGL for Matlab low-level functions, as far as they are available,
work very well for many applications, but a few OpenGL functions are
not yet supported or incomplete. Look into the PsychOpenGL/MOGL/wrap/
folder for a listing of all OpenGL functions. Functions prefixed with
an underscore are not yet enabled. Given the enormous size and complexity
of the OpenGL API we don't have any ressources to validate all functions
for their correctness, but MOGL is used for pretty complex projects by
some of the developers, so most common functions are known to be bug-free
and bugs are quickly fixed if we find them.

PsychHID and the DAQ toolbox: (Denis Pelli)

PsychHID is known to work perfectly well for keyboard queries, but the
functions for low-level USB-HID access are known to have some unresolved
stability issues on some systems as of 6.10.2006. The DAQ toolbox depends
on these functions and therefore may suffer from problems on some setups.
Also the DAQ toolbox itself has to be considered beta quality, so prepare
for a slightly bumpy ride if you use it.

MICROSOFT WINDOWS version of the OpenGL Psychtoolbox: (Mario Kleiner)

The Windows version of PTB is a hybrid of the old Windows PTB 2.54 and
parts of the new OS-X PTB. All M-Files are identical to the OS-X version.
The "Screen" command is nearly identical to the OS-X version, as well as
the ShowCursor, HideCursor, GetMouse, SetMouse and KbName commands.
Many other Mex files are taken from the old PTB. As far as functions are
implemented, they are considered to be identical in functionality, behaviour
and quality as their OS-X counterparts, unless otherwise noted in the
help of the functions. There are gaps and deviation though:

The very sophisticated FONT functions for query, manipulation and handling
of fonts are only present in the OS-X version. They are non-existent in
the Windows version, without any plans to implement them.

PsychHID is missing, therefore the DAQ toolbox and other toolboxes based
on PsychHID are not available on Windows. It wouldn't be difficult for an
experienced C programmer to implement PsychHID though. Any volunteers?

PsychSound is missing.


Multidisplay support is implemented with a slightly different behaviour due to
differences in the way OS-X and Windows handle multiple displays. They are
equivalent in functionality, but the assignment of screen numbers to displays
is different, so you will need to take this into account if you want to
write portable scripts that use this feature.

There are more differences, but most common experiment scripts should work
identically on OS-X and Windows.


GNU/LINUX version of Psychtoolbox: (Mario Kleiner)

See MS-Windows version for missing features. In some areas of
functionality the Linux version is at parity or even ahead of the OS/X
Psychtoolbox.


GNU/Octave support: (Mario Kleiner)

Psychtoolbox can be used with GNU/Octave version 3.2 instead of Matlab,
allowing for complete independence from proprietary/commercial software.


There are probably a few more incomplete areas, but these are the ones i am
aware of. If in doubt, ask on the Psychtoolbox forum and check the Wiki
section about "Platform Differences and Writing Portable Code".
http://www.psychtoolbox.org/forum.html

Good luck
Mario Kleiner, 11.06.2011.