kalmar
/
GroupRings.jl
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add divexact function

This commit is contained in:
kalmar 2017-07-11 15:58:45 +02:00
parent 27e0b03b3c
commit e92a5d72e8
1 changed files with 11 additions and 1 deletions
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12
src/GroupRings.jl
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@ -1,7 +1,7 @@
module GroupRings
using Nemo
import Nemo: Group, GroupElem, Ring, RingElem, parent, elem_type, parent_type, mul!, addeq!
import Nemo: Group, GroupElem, Ring, RingElem, parent, elem_type, parent_type, mul!, addeq!, divexact
import Base: convert, show, hash, ==, +, -, *, //, /, length, norm, rationalize, deepcopy_internal, getindex, setindex!, eltype, one, zero
@ -368,6 +368,16 @@ function *{T<:Number, S<:Number}(X::GroupRingElem{T}, Y::GroupRingElem{S})
return GroupRingElem(result, RG)
end
function divexact{T}(X::GroupRingElem{T}, Y::GroupRingElem{T})
if length(Y) != 1
throw("Can not divide by a non-primitive element $(Y)!")
else
idx = findfirst(Y)
c = Y[idx]
g = parent(Y).basis[idx]
return X*1//c*parent(Y)(inv(g))
end
end
###############################################################################
#
# *-involution