MeatAxe
2.4
Programs for working with modular representations

mkhom [Options] [ts] [rl] [b Mode] [H Dim] M N Hom
This program calculates a basis for the vector space of homomorphisms between two kGmodules, Hom_{kG}(M,N). In the case M=N the program optionally finds a generating set for the algebra of endomoprhisms, End_{kG}(M), and calculates the corresponding left or right regular representation.
If used without any options, mkhom
writes the spinning basis of M to M.std, and a kbasis of the homomorphism space to Hom.1, Hom.2,... The latter are given with respect to the spinning basis of M and the original basis of N. To get the homomorphisms with respect to the original bases of M and N, multiply the matrices from the left with the inverse of Hom.
mkhom
uses peak words of the first module. Thus, before using the program, chop and pwkond must have been run on the first module.
The algorithm used by this program was developed by Magdolna SzĂ¶ke [Sz98].