The frequency table for 1799 donor sites (Stephens and Schneider J. Mol. Biol., 228, 1124-1136, 1992), f(b,l) (where b is the base A,C,G or T and l is the position in the site) was used with a random number generator to create 100 sequences that resemble donor sites. These sequences were used used to create a sequence logo. Since there were only 100 sequences, the resulting logo is slightly different from the original.
The process described above was repeated 50 times and the logos were combined using the imagemagick convert program to make the movie.
The logo jiggles because 100 is a small (!) number of samples. This method gives one a sense for how much a logo varies depending on sequence.
The program that creates a single distribution from a ribl is ridi.
Schneider Lab
origin: 2002 November 1
updated: 2002 November 1