From 70cde4467331ce6abc32aa43848523b9c5e7bbaa Mon Sep 17 00:00:00 2001
From: kalmarek <kalmar@amu.edu.pl>
Date: Wed, 8 Nov 2017 11:09:29 +0100
Subject: [PATCH] much faster generate_balls (using Base.product)

---
 src/Groups.jl | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/Groups.jl b/src/Groups.jl
index d471d81..71929b7 100644
--- a/src/Groups.jl
+++ b/src/Groups.jl
@@ -390,6 +390,17 @@ function generate_balls{T<:GroupElem}(S::Vector{T}, Id::T=parent(first(S))(); ra
     return B, sizes
 end
 
+function generate_balls{T<:RingElem}(S::Vector{T}, Id::T=one(parent(first(S))); radius=2, op=*)
+    sizes = Int[]
+    B = [Id]
+    for i in 1:radius
+        BB = [op(i,j) for (i,j) in Base.product(B,S)]
+        B = unique([B; vec(BB)])
+        push!(sizes, length(B))
+    end
+    return B, sizes
+end
+
 ###############################################################################
 #
 #   Includes