Schubert Galois groups in the Grassmannian G(4,9)

Index to code to run the Frobenius algorithm and to classify Schubert Galois grpoups.


This directory contains source code for Robert Williams's implementation of the Frobenius algorithm for Schubert Galois groups in G(4,9), and his code to classify Schubert Galois groups by the frequency of cycle types of these Frobenius elements.
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Williams.tar gzipped .tar file of these files
README The README file
FrobAlg.py Robert's implementation of the Frobenius algorithm for studying a list of Schubert problems. It is in Python2, runs Singular, and uses the Singular library schubert.lib. It reads Schubert problems in a particular format, in schubertprob.txt (This is formatted by the Python script prettyFormat.py from our Python library in the checkerboard game, and the format is explained in FrobAlg.py). For each, it runs the Frobenius algorithm, determining if it is the full symmetric group, or if it cannot tell. With suitable modification, it can be used to test other lists of Schubert problems.
schubertprob.txt This contains the initial list of Schubert problems to be tested. This was the output of the the Python implementation of Vakil's algorithm, and is the file from the computations on G49.
schubert.lib Singular library for computing Schubert problems.
Full_Symmetric_Group.txt These are the Schubert problems that it found has full symmetric Galois groups.
Unknown_Galois_Group.txt These are the Schubert problems that is could not tell if they had full symmetric Galois groups.
schubert_template.sing This is a template file. It should not be altered.
SchubertStats.py This takes a list of Schubert problems in Unknown_Galois_Group.txt and tries to compute 50,000 Frobenius elements (this can be changed in the file) for the problem, writing the output to a text file Schubert_Stats.txt that, for each Schubert problem in Unknown_Galois_Group.txt contains both a plain text frequency table of the cycle types found, as well as a formatted LaTeX table. It uses both schubert.lib and cycle_sample.sing.
cycle_sample.sing This is a template file. It should not be altered. It could be deleted.
Schubert_Stats.txt The output from SchubertStats.py.
Simplify.py This Python 3 script reads Schubert_Stats.txt and writes just the lines with the Schubert problems and ASCII frequency table to the file Raw_data.txt
Raw_data.txt The output file from Simplify.py.
makeHtml.py A Python3 script that reads Raw_data.txt and writes it into a .html file Frobenius_Raw.html. It needs the file procedures.py.
procedures.py Procedures for makeHtml.py
Frobenius_Raw.html The raw data in .html format. This requires .gif files of Young tableaux, which is available in the .tarball Tableaux.tar.
Tableaux.tar All the tableaux for Frobenius_Raw.html

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Last modified: Sun Feb 3 10:52:23 CST 2019