Powermap( tbl, prime )
Powermap( tbl, prime, parameters )
returns a list of possibilities for the prime-th powermap of the character table tbl.
The optional record parameters may have the following fields:
chars:
a list of characters which are used for the check of
kernels (see ConsiderKernels), the test of congruences (see
Congruences) and the test of scalar products of symmetrisations (see
PowermapsAllowedBySymmetrisations); the default is tbl.irreducibles
powermap:
a (parametrized) map which is an approximation of
the desired map
decompose:
a boolean; if true, the
symmetrisations of chars must have all constituents in chars,
that will be used in the algorithm; if chars is not bound and
tbl.irreducibles is complete, the default value of
decompose is true, otherwise false
quick:
a boolean; if true, the subroutines are
called with the option "quick"; especially, a unique map will be
returned immediately without checking all symmetrisations; the default value
is false
parameters:
a record with fields maxamb, minamb
and maxlen which control the subroutine PowermapsAllowedBySymmetrisations:
It only uses characters with actual indeterminateness up to maxamb,
tests decomposability only for characters with actual indeterminateness at
least minamb and admits a branch only according to a character
if there is one with at most maxlen possible minus-characters.
# cf.\ example in "InitPowermap"
gap> t:= CharTable( "U4(3).4" );;
gap> pow:= Powermap( t, 2 );
[ [ 1, 1, 3, 4, 5, 2, 2, 8, 3, 4, 11, 12, 6, 14, 9, 1, 1, 2, 2, 3, 4,
5, 6, 8, 9, 9, 10, 11, 12, 16, 16, 16, 16, 17, 17, 18, 18, 18,
18, 20, 20, 20, 20, 22, 22, 24, 24, 25, 26, 28, 28, 29, 29 ] ]