MatScalarProducts( tbl, chars1, chars2 )
MatScalarProducts( tbl, chars )
For a character table tbl and two lists chars1, chars2 of characters, the first version returns the matrix of scalar products (see ScalarProduct); we have
'MatScalarProducts( <tbl>, <chars1>, <chars2> )[i][j]' = 'ScalarProduct( <tbl>, <chars1>[j], <chars2>[i] )',
i.e., row i
contains the scalar products of chars2[i]
with all
characters in chars1.
The second form returns a lower triangular matrix of scalar products:
'MatScalarProducts( <tbl>, <chars> )[i][j]' = 'ScalarProduct( <tbl>, <chars>[j], <chars>[i] )'
for 'j' leq 'i'.
gap> t:= CharTable( "A5" );; gap> chars:= Sublist( t.irreducibles, [ 2 .. 4 ] );; gap> chars:= Set( Tensored( chars, chars ) );; gap> MatScalarProducts( t, chars ); [ [ 2 ], [ 1, 3 ], [ 1, 2, 3 ], [ 2, 2, 1, 3 ], [ 2, 1, 2, 2, 3 ], [ 2, 3, 3, 3, 3, 5 ] ]
GAP 3.4.4