KnotPlot Control Panel (Main)
Note: This page explains the main control panel (there's more than one). If you're just
starting with KnotPlot, you might want to begin with the top page of the
(can also be accessed by using the
or by clicking the 'Man' button.)
I'll go through the control panel from the top down, explaining each feature in turn.
- Click on one of the buttons at the top to load some knots, randomly selected, from the
The 'All' button chooses a knot from the entire catalogue, the numbered buttons choose a link with
that many components. The 'Sp' button picks a knot selected at random from the
- Yes, it's true, the 'Quit' button terminates KnotPlot. You can also do this by typing in the
commands 'quit', 'exit', or 'stop', by hitting the ESC-key or by selecting 'Quit' from the
- The 'Zoo' button will bring up an assortment of knots and links, selected from the catalogue at
random. Click on the one you want and it'll be loaded. You can also use the
command to display the knot catalogue in order, starting from a given point.
- There are a number of pre-packaged demos ready to run. Click on 'Demo' in the Main control
panel, then click on 'Load Demos' Using the demos is explained on
- Click on the 'Edit' button if you want to pull the knot around. Note that it is possible to
change the knot type with the method. A very brief explanation of
- Some of KnotPlot's dynamics may be controlled with the bottom part of this control panel,
however, many more options are available on the
dynamics control panel.
Click on the 'Dyn' button to go there.
- Clicking on the 'Help' button will start a WWW browser and load this page. Other control
panels may also have a 'Help' button which will provide information on that control panel.
- The 'Man' button will start the WWW browser at the top page of the KnotPlot Manual.
- To sketch a knot, click on 'Draw'. Sketching is explained on a
- A number of special objects may be drawn along with knots or links. These can be selected
using the radio buttons or by using the
- Various kinds of grids, useful when sketching. The parameter
controls the kind of grid drawn.
- The knot energy, currently the minumum distance energy as defined by Simon. You can watch the
energy change during relaxation. Note that this will slow down relaxation considerably as it is a
fairly expensive calculation. It can be useful setting
to something around 10 to (often greatly) improve performance.
- A coloured backdrop, just for fun.
- xyz axes and bead labels.
- The spin plane. When the spin plane is on it may be moved using the Shift key and the mouse
buttons in the view window.
All the parameters in this section control how the knot is displayed. In addition, some of them
will affect any surface geometry exported by KnotPlot. Nothing in this section affects the
underlying mathematical object (that is, what is read and written with the
To get a feel for how things work try loading a knot at random (see above) and then click on the
two large buttons labelled 'Smooth Tubes' and 'Beads and Sticks'. This will show you the two
principal methods of displaying knots. The beads and sticks closely approximate the actual
mathematical object. KnotPlot starts out in a smooth tube mode, mostly because knots look prettier
in this mode.
- You can rotate the view seen in the view window by using a virtual trackball (left mouse) and
translate the view by using the right mouse in the view window. These transformations may be
undone, and the view restored to the default orientation by clicking on the 'untran' button.
- Sometimes, especially if
is too small, you'll see a funny crimp in the knot or link's surface at the point at which the
drawing begins and ends for each component. There are technical reasons for this that are
explained elsewhere. For the present you can get rid of this deficit angle by clicking on the
'twfix' button (twist fix). There is also a
command that does the same job (and more).
- To reset the display, click on the 'reset' button in the right of the display section. This
reset button also resets pretty much everything else in the program, including 4D parameters,
Postscript output, the dynamics, and what knot.
- Don't ask me why the 'scale' slider is on top all by itself. The drawing scale can also be
changed by using the middle mouse button in the view window.
- The 'norm', 'spec', 'brok', 'sbro', 'flat', 'hflat' buttons need explaining, try them out when
you're in 'Smooth Tubes' mode.
All of the parameters for the dynamics may be changed while relaxation is taking place. The same
thing applies to any display parameters. Just remember you may have to click and hold down the
left mouse button over the control panel until you see some visual feedback in the case where a
large knot is being relaxed.
Be sure to read the page on
to see other options.
- The default dynamical model is a damped force law with collision avoidance. This is what you
get if you click the button 'A' in the dynamics section. The other main force law of interest is
an undamped force law without collision checking. You can get this by clicking 'B'. Another
interesting combination is 'Damped' with 'Collide'. This speeds up the relaxation but allows for
possible change of knot type. The 'Init' button initializes the dynamical model to the default
setting (including all the slider positions).
- Click on the 'Go' button to watch the knot relax. The 'Go' button will turn into a red 'Stop'
button while relaxation is taking place. Sometimes, if your knot is quite large, you may have to
click and hold down the mouse button over the 'Stop' button until something happens.
- The 'zero' button zeros the velocities of all the beads. This is only applicable to undamped
This HTML file was produced at 6:10 p.m. on July 11, 1996 directly
from the LaTeX source.
main WWW site ], [