kalmar/Groups.jl
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use additive group for objects involving Rings

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kalmar 2017-07-12 21:11:50 +02:00
parent a5a67bd7d3
commit d2cb646119
1 changed files with 12 additions and 4 deletions
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16
src/DirectProducts.jl
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@ -152,9 +152,13 @@ end
###############################################################################
function direct_mult(g::DirectProductGroupElem, h::DirectProductGroupElem)
parent(g) == parent(h) || throw("Can't multiply elements from different groups: $g, $h")
G = parent(g)
return G([op(a,b) for (op,a,b) in zip(G.operations, g.elts, h.elts)])
G = parent(g)
# G == parent(h) || throw("Can't multiply elements from different groups: $G, $parent(h)")
if isa(first(G.factors), Ring)
return G(.+(g.elts,h.elts))
else
return G(.*(g.elts,h.elts))
end
end
doc"""
@ -179,7 +183,11 @@ doc"""
# TODO: dirty hack around `+` operation
function inv(g::DirectProductGroupElem)
G = parent(g)
return G([(op == (*) ? inv(elt): -elt) for (op,elt) in zip(G.operations, g.elts)])
if isa(first(G.factors), Ring)
return DirectProductGroupElem([-a for a in g.elts])
else
return DirectProductGroupElem([inv(a) for a in g.elts])
end
end
###############################################################################