From 3c0ae5baf0c1bbcd685f4d11f43fee62769c1ff7 Mon Sep 17 00:00:00 2001
From: kalmar <kalmar@amu.edu.pl>
Date: Thu, 8 Jun 2017 21:45:46 +0200
Subject: [PATCH] dispatch splaplacian on GroupRing{T} type

with multiplicative unit for Rings
---
 src/PropertyT.jl |  2 +-
 src/sdps.jl      | 16 ++++++++++++----
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/PropertyT.jl b/src/PropertyT.jl
index a98a302..0140075 100644
--- a/src/PropertyT.jl
+++ b/src/PropertyT.jl
@@ -5,7 +5,7 @@ using GroupRings
 using Memento
 
 using Groups
-import Nemo: Group, GroupElem
+import Nemo: Ring, Group, GroupElem
 
 const logger = Memento.config("info", fmt="{msg}")
 const solver_logger = Memento.config("info", fmt="{msg}")
diff --git a/src/sdps.jl b/src/sdps.jl
index 6b26e74..27fa87e 100644
--- a/src/sdps.jl
+++ b/src/sdps.jl
@@ -13,10 +13,18 @@ function constraints_from_pm(pm, total_length=maximum(pm))
     return constraints
 end
 
-function splaplacian(RG::GroupRing, S, Id=RG.group(),
-   n=length(RG.basis), T::Type=Int)
-    result = RG(spzeros(n))
-    result[Id] = float(length(S))
+function splaplacian{TT<:Group}(RG::GroupRing{TT}, S, Id=RG.group(), T::Type=Int)
+    result = RG(T)
+    result[Id] = T(length(S))
+    for s in S
+        result[s] -= one(T)
+    end
+    return result
+end
+
+function splaplacian{TT<:Ring}(RG::GroupRing{TT}, S, Id=one(RG.group), T::Type=Int)
+    result = RG(T)
+    result[Id] = T(length(S))
     for s in S
         result[s] -= one(T)
     end