Using the LinKnot package

2008-12-16T16:17:21Z

BocmoNpasc: trcrolc4tcs

vinoacell
{{Manual TOC Sidebar}}

The Mathematica package [http://www.mi.sanu.ac.yu/vismath/linknot/ ''LinKnot''] is a combination of two packages. The first, "Knot2000" was written by M. Ochiai and N. Imafuji. This was extended to the package ''LinKnot'' by S. Jablan and R. Sazdanovic. This package provides many useful things KnotTheory can't do natively; for example, it can interpret Conway notation, and, at least on Windows machines, provides nice graphics for knots, and a graphical interface for drawing knots by hand.

(''LinKnot'' also has a [http://math.ict.edu.yu/ webMathematica interface]!)

There are two ways ''LinKnot'' can be used along with <tt>KnotTheory`</tt>:
* As a "subcontractor": ''LinKnot'' is mostly hidden and wrapper functions are provided to access some of its functionality from within <tt>KnotTheory`</tt>.
* In parallel: everything from both packages is visible.

The advantage for the first approach is that the interface to ''LinKnot'' is then consistent with the conventions used by <tt>KnotTheory`</tt> and the Mathematica name space remains less cluttered. The advantage of the second approach is obvious - with it, all the functionality of ''LinKnot'' is available, and not just the parts for which wrapper functions are provided within <tt>KnotTheory`</tt>.

====Using ''LinKnot'' as a "subcontractor"====
To use ''LinKnot'' from within ''KnotTheory'', download the file <tt>LinKnot.zip</tt> from the [http://www.mi.sanu.ac.yu/vismath/linknot/ LinKnot site] or from [http://katlas.math.toronto.edu/svn/LinKnot/tags/stable/ our mirror]. Unzip and install the content of <tt>LinKnot.zip</tt> wherever you like, and within Mathematica issue a command like

{{Startup Note}}



{{In|
n = 2 |
in = <nowiki>AppendTo[$Path, "/path/to/LinKnots.m"];</nowiki>}}


After you've done this, everything should just work. (''LinKnot'' will only be loaded when necessary, and there might be a short delay when this happens.) If everything doesn't just work, please complain to [[User:Scott|Scott]].

In case of problems, you may find it helpful to explicitly set the path in which you've installed ''LinKnot'' (although ''KnotTheory'' tries to do this itself). Simply set <tt>LinKnotDirectory[]</tt>.



{{HelpLine|
n = 3 |
in = <nowiki>LinKnotDirectory</nowiki> |
out= <nowiki>LinKnotDirectory[] contains the path to the ''LinKnot'' package. It must be set correctly in order for all the (Windows only) MathLink components of ''LinKnot'' to be usable. It can be overriden by the user.</nowiki>}}


====Using ''LinKnot'' in parallel with <tt>KnotTheory`</tt>====
To use ''LinKnot'' in parallel with <tt>KnotTheory`</tt>, you should [http://www.mi.sanu.ac.yu/vismath/linknot/LinKnot.zip download LinKnot.zip] from the [http://www.mi.sanu.ac.yu/vismath/linknot/ LinKnot site] (a full ''LinKnot'' manual page ManualK2KC.nb is in the zip file, and the main file is the mathematica notebook <tt>K2KL.nb</tt>). After downloading the file LinKnot.zip:

# Extract LinKnot.zip anywhere (e.g., to the local disc "C:\"). It will automatically create a new folder <tt>LinKnot</tt>.
# Set the directory to <tt>LinKnot</tt>, add the path to <tt>KnotTheory`</tt> to the Mathematica <code>$Path</code>, and run:

<pre>
SetDirectory["/path/to/LinKnot/"];
<< LinKnots`
AppendTo[$Path, "Path to KnotTheory"];
<< KnotTheory`
</pre>

For example, if ''LinKnot'' is installed in "C:\LinKnot" and <tt>KnotTheory`</tt> is installed at "C:\KnotTheory", run:

<pre>
SetDirectory["C:\\LinKnot"];
<< LinKnots`
AppendTo[$Path, "C:\\"];
<< KnotTheory`
</pre>

Then you can work with the both programs <tt>KnotTheory`</tt> and ''LinKnot''.

If you need to have the complete program ''LinKnot'' visible (with the usage, description of all ''LinKnot'' functions, ''etc''.) and run together <tt>KnotTheory`</tt> and ''LinKnot'', you can open the file <tt>K2KL.nb</tt> from the directory <tt>LinKnot</tt> and run the same command as before.

After you've done this, everything should just work. If everything doesn't just work, please complain to S. Jablan (jablans@yahoo.com).

====Further usage notes by [[User:Jablans|Jablans]]====

If you have any problem with running ''LinKnot'' (as a separate program) please do the following:

# in your ''Mathematica'' directory (e.g., C:\Program Files\Wolfram Research\Mathematica\5.0) make a new folder named LinKnot;
# extract the contents of the file LinKnot.zip into the directory LinKnot;
# open the "Mathematica" notebook K2KL.nb that you will find in the directory LinKnot;
# run the first line:

<pre>
SetDirectory["LinKnot"]
<< LinKnots.m
</pre>

Then you can fix the appropriate path and work with ''KnotTheory'' and ''LinKnot'' as well.

====See also====

See also [[Extending/Modifying KnotTheory`#Lessons learnt from integrating LinKnot`]] for technical details on how LinKnot` and KnotTheory` were integrated.

Knot Atlas - User contributions [en]

Using the LinKnot package