# Graphical Input

Thanks to our link with LinKnot, on Windows systems KnotTheory` accepts graphical knot input.

(For In[1] see Setup)

As in the section Using the LinKnot package, the first step is to add LinKnot to the Mathematica search path. This path will likely be different on your computer.

 `In[2]:=` `AppendTo[\$Path, "C:/bin/LinKnot/"];`
 In[3]:= ?KnotInput KnotInput[] opens a window in which you can draw a knot or link by hand. Right click and select 'Quit' when you're done. This function requires the package LinKnots`, and will only run on Windows machines. Sorry!
 In[4]:= KnotInput::about The KnotInput program was written by M. Ochiai, C. Nakai, Y. Matsuyama and N. Imafuji and is imported to KnotTheory` via the package LinKnot by S. Jablan and R. Sazdanovic

Thus for example, the input line

 `In[5]:=` `K = KnotInput[]`

pops a blank window on which a knot or a link can be drawn with mouse clicks. At first pass all crossings are drawn as "new over old", but a further click on any given crossing will flip it.

KnotInput in action.

A right click followed by selecting "quit" will then determine the Gauss code of the knot or link just drawn and return it to Mathematica:

 `Out[5]=` `GaussCode[{-1,-4,2,3},{-3,-5,4,6},{5,1,-6,-2}]`

K is now perfectly usable within KnotTheory`:

 `In[5]:=` `Kh[K][q, t]` `Out[5]=` ``` 3 5 7 2 11 3 9 4 11 4 13 4 q + q + q t + q t + q t + 3 q t + 2 q t```