Inputting Your Own Lattice

Give an URL

You need to make a lattice file (as described below) and put it in a place where it can be accessed as an URL. If you have a homepage you could put this lattice file in the same (or a subdirectory of the) directory that has your homepage. If you homepage has the URL

http://www.myuniv.edu/~yourname
and your lattice file, say foo.lat, is in the same directory as your homepage, then fill in the text field on the applet with

http://www.myuniv.edu/~yourname/foo.lat

If you don't have a homepage your system administrator should be able to tell you what directory to put the file in.

Lattice File Format

Here is the lattice N₅

Here is the lattice file for it:

(
 (0 (b c))
 (b (1))
 (c (a))
 (a (1))
 (1 ())
)

Note this is a list and each element is also a list which gives the element and a list of its upper covers.

Pointers

Elements can be any (reasonable) string.
Note that the top of the lattice, 1 in this case, needed the empty list for its list of covers; you cannot just omit it.
Linebreaks are treated as whitespace so the above example could be all on one line.
Everything before the first left parenthesis and after the matching right parenthesis is ignored so comments can be include (but the ones before the lattice should not have any parentheses).

Extensions

You can add a short label after the first parenthesis in the lattice.
You can specify one of 5 colors for each edge of the diagram. 1 = red, 2 = yellow, 3 = white, 4 = blue, 5 = black.
So the N₅ file with colors and a label is

(n5
 (0 ((b 1) (c 2)))
 (b ((1 3)))
 (c ((a 4)))
 (a ((1 5)))
 (1 ())
)

Back to the Lattice Drawing Page.

Last updated: Thurs. Sept. 12
Ralph Freese