NAME
Math::ematica - Perl extension for connecting Mathematica(TM)
SYNOPSIS
use Math::ematica qw(:PACKET :TYPE :FUNC);
WARNING
This is alpha software. User visible changes can happen any
time.
The module is completely rewritten. Literally no line of the old
stuff is used (don't ask - I've learned a few things since these
days ;-). If you are using the old 1.006 version, note that the
interface has changed. If there is an overwhelming outcry, I
will provide some backward compatibility stuff.
Feel free to suggest modifications and/or extensions. I don not
use Mathematica for real work right now and may fail to foresee
the most urgent needs. Even if you think that the interface is
great, you are invited to complete the documentation (and fix
grammos and typos). Since I am no native English speaker, I will
delay the writing of real documentation until the API has
stabilized.
I do develop this module using Mathematica 3.0.1 on a Linux
2.0.30 box. Let me know, if it does work with other versions of
Mathematica or does not work on other *nix flavors.
DESCRIPTION
The `Math::ematica' module provides an interface to the
MathLink(TM) library. Functions are not exported and should be
called as methods. Therefore the Perl names have the 'ML' prefix
stripped. Since Perl can handle multiple return values, methods
fetching elements from the link return the values instead of
passing results in reference parameters.
The representation of the data passed between Perl and
Mathematica is straight forward exept the symbols which are
represented as blessed scalars in Perl.
Exported constants
`PACKET'
The `PACKET' tag identifies constants used as packet types.
print "Got result packet" if $link->NextPacket == RETURNPKT;
`TYPE'
The `TYPE' tag identifies constants used as elements types.
print "Got a symbol" if $link->GetNext == MLTKSYM;
Exported functions
`FUNC'
The `FUNC' tag currently only contains the `symbol'
function which returns the symbol for a given name.
$sym = symbol 'Sin';
The plain interface
This set of methods gives you direct access to the MathLink
function. Don't despair if you don't know them too much. There
is a convenient layer ontop of them ;-). Methods below are only
commented if they do behave different than the corresponding C
functions. Look in your MathLink manual for details.
`new'
The constructor is just a wrapper around `MLOpenArgv'.
$ml = new Math::ematica '-linklaunch', '-linkname', 'math -mathlink';
The link is automatically activated on creation and will be
closed upon destruction.
`ErrorMessage'
print $link->ErrorMessage;
`EndPacket'
`Flush'
`NewPacket'
`NextPacket'
`Ready'
`PutSymbol'
`PutString'
`PutInteger'
`PutDouble'
`PutFunction'
`GetNext'
`GetInteger'
`GetDouble'
`GetString'
The method does the appropriate `MLDisownString' call for you.
`GetSymbol'
The module does the appropriate `MLDisownSymbol' call for you.
It also blesses the result string into the package
`Math::ematica::symbol'.
`Function'
Returns the function name and argument count in list context. In
scalar contex only the function name is returned.
`GetRealList'
Returns the array of reals.
The convenience interface
`PutToken'
Puts a single token according to the passed data type.
$link->PutToken(1); # MLPutInteger
Symbols are translated to `MLPutFunction' if the arity is
provided as aditional parameter.
$link->PutToken(symbol 'Pi'); # MLPutSymbol
$link->PutToken(symbol 'Sin', 1); # MLPutFunction
`read_packet'
Reads the current packet and returns it as nested data
structure. The implementaion is not complete. But any packet
made up of `MLTKREAL', `MLTKINT', `MLTKSTR', `MLTKSYM', and
`MLTKFUNC' should translate correctely. A function symbol `List'
is dropped automatically. So the Mathematica expression
`List[1,2,3]' translates to the Perl expression `[1,2,3]'.
*Mabybe this is *too* convenient?*.
`call'
Call is the main convenience interface. You will be able to do
most if not all using this call.
Note that the syntax is nearly the same as you are used to as
*FullForm* in Mathematica. Only the function names are moved
inside the brackets and separated with ',' from the arguments.
The method returns the nested data structures read by
`read_packet'.
$link->call([symbol 'Sin', 3.14159265358979/2]); # returns something near 1
To get a table of values use:
$link->call([symbol 'Table',
[symbol 'Sin', symbol 'x'],
[symbol 'List', symbol 'x', 0, 1, 0.1]]);
This returns a reference to an array of doubles.
You may omit the first `symbol'. *Maybe we should choose the
default mapping to *Symbol* an require *Strings*s to be marked?*
`install'
If you find this too ugly, you may `install' Mathematica
functions as Perl functions using the `install' method.
$link->install('Sin',1);
$link->install('Pi');
$link->install('N',1);
$link->install('Divide',2);
Sin(Divide(Pi(),2.0)) # should return 1 (on machines which can
# represent '2.0' *exactely* in a double ;-)
The `install' method takes the name of the mathematica function,
the number of arguments and optional the name of the Perl
function as argument.
$link->install('Sin',1,'sin_by_mathematica');
Make shure that you do not call any *installed* function after
the `$link' has gone. Wild things will happen!
`send_packet'
Is the sending part of `call'. It translates the expressions
passed to a Mathematica package and puts it on the link.
`register'
This method allows to register your Perl functions to
Mathematica. *Registered* functions may be called during
calculations.
sub addtwo {
$_[0]+$_[1];
}
$link->register('AddTwo', \&addtwo, 'Integer', 'Integer');
$link->call([symbol 'AddTwo',12, 3]) # returns 15
You may register functions with unspecified argument types using
undef:
sub do_print {
print @_;
}
$link->register('DoPrint', undef);
$link->call(['DoPrint',12]);
$link->call(['DoPrint',"Hello"]);
AUTHOR
Ulrich Pfeifer
SEE ALSO
See also the perl(1) manpage and your Mathematica and MathLink
documentation. Also check the t/*.t files in the distribution.
ACKNOWLEDGEMENTS
I wish to thank Jon Orwant of *The Perl Journal*, Nancy Blachman
from *The Mathematica Journal* and Brett H. Barnhart from
*Wolfram Research*.
Jon brought the earlier versions of this module to the attention
of Nancy Blachman. She in turn did contact Brett H. Barnhart who
was so kind to provide a trial license which made this work
possible.
So subscribe to *The Perl Journal* and *The Mathematica Journal*
if you are not subscribed already if you use this module (a
Mathematica license is needed anyway). You would be nice to nice
people and may even read something more about this module one
day ;-)
Copyright
The Math:ematica module is Copyright (c) 1996,1997 Ulrich
Pfeifer. Germany. All rights reserved.
You may distribute under the terms of either the GNU General
Public License or the Artistic License, as specified in the Perl
README file.
Mathematica and MathLink are registered trademarks of Wolfram
Research.