applysym.html

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<TD>Author</TD>
<TD>Thomas Wolf</TD></TR>
<TR>
<TD>Title</TD>
<TD><font face="Courier New">APPLYSYM</font></TD></TR>
<TR>
<TD>Short description</TD>
<TD>
The package <font face="Courier New">APPLYSYM</font> takes as input
a differential equation (DE) or a system of DEs and its
point symmetries, for example computed by the program
<a href="liepde.html"><font face="Courier New">LIEPDE</font></a>.
It computes symmetry and similarity variables through solving single
first order partial DEs (PDEs) with the procedure
<font face="Courier New">QUASILINPDE</font></a>. 
This procedure formulates an equivalent
characteristic non-linear system of ordinary DEs (ODEs) which 
is investigated by the program
<a href="crack.html"><font face="Courier New">CRACK</font></a>.
Although the program <font face="Courier New">CRACK</font> is
primarily made for dealing with overdetermined DE-systems, it
nevertheless has good chances of solving the not overdetermined
characteristic ODE-systems because 
<font face="Courier New">CRACK</font> has a number of different
integration techniques built in and because
Lie-symmetries often have a simple
form which results in relatively simple characteristic ODE-systems.
The program <font face="Courier New">QUASILINPDE</font></a> can be
used independently without connection to symmetries for solving
quasi-linear first order PDEs as demonstrated in 
<font face="Courier New">applysym.tst</font>.
</TD></TR>
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<TD>Platform</TD>
<TD>REDUCE, version 3.6 or 3.7</TD></TR>
<TR>
<TD>System requirements</TD>
<TD>The memory requirements depend crucially on the
application. The non-trivial computations in the test file 
<a href="ftp://ftp.maths.qmw.ac.uk/pub/tw/applysym/applysym.tst">
<font face="Courier New">applysym.tst</font></a>
have been run in a 4MB session under LINUX. 
</TD></TR>
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<TD>Installation</TD>
<TD>In a running REDUCE session either do <br>
<font face="Courier New"> &nbsp; in "applysym.red"$ </font> <br>
or, in order to speed up computation, either compile it with <br>
<font face="Courier New"> &nbsp; on comp$ </font> <br>
before the above command, or, generate a fast-loading compiled file once with <br>
<font face="Courier New"> &nbsp; faslout "applysym"$ </font> <br>
<font face="Courier New"> &nbsp; in "applysym.red"$ </font> <br>
<font face="Courier New"> &nbsp; faslend$ </font> <br>
and load that file whenever you want to run 
<font face="Courier New">APPLYSYM</font> with <br>
<font face="Courier New"> &nbsp; load applysym$ </font> <br>
In a similar way proceed with the files 
<font face="Courier New">crack.red, liepde.red</font>.
The above commands assume all files to be in the current directory. 
</TD></TR>
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<TD>More information/updates </TD>
<TD>There are available a 
<a href="ftp://ftp.maths.qmw.ac.uk/pub/tw/applysym/applysym.tex">manual</a>, a
<a href="ftp://ftp.maths.qmw.ac.uk/pub/tw/applysym/applysym.tst">test file</a> 
and a
<a href="ftp://ftp.maths.qmw.ac.uk/pub/tw/applysym/applysym.rlg">log file</a>. 
<br>
A web demo for <font face="Courier New">APPLYSYM</font> may be available
later. The latest version is available from 
<a href="ftp://ftp.maths.qmw.ac.uk/pub/tw/applysym/">
ftp://ftp.maths.qmw.ac.uk/pub/tw/applysym/</a>. <br>
</TD></TR>
<TR>
<TD>Contact</TD>
<TD>e-mail: <a href="mailto:T.Wolf@maths.qmw.ac.uk">
Thomas Wolf</a></TD></TR></TABLE></BODY></HTML>






