Review and revise API

Author: ranjanan

src/AMG.jl

@@ -1,10 +1,10 @@
 module AMG
 
 include("strength.jl")
-export classical
+export strength_of_connection, Classical
 
 include("splitting.jl")
-export RS
+export split_nodes, RS
 
 include("gallery.jl")
 export poisson

src/classical.jl

@@ -0,0 +1,33 @@
+struct Solver{S,T,P,PS}
+    strength::S
+    CF::T
+    presmoother::P
+    postsmoother::PS
+    max_levels::Int64
+    max_coarse::Int64
+end
+
+function ruge_stuben(A::SparseMatrixCSC;
+                strength = Classical(),
+                CF = RS(),
+                presmoother = GaussSiedel(),
+                postsmoother = GaussSiedel(),
+                max_levels = 10,
+                max_coarse = 500)
+
+        s = Solver(strength, CF, presmoother,
+                    postsmoother, max_levels, max_levels)
+
+        levels = [Level(A)]
+
+        while length(levels) < max_levels && size(levels[end].A, 1)
+            extend_heirarchy!(levels, strength, CF, A)
+        end
+end
+
+function extend_heirarchy!(levels::Vector{Level}, strength, CF, A)
+
+    S = strength_of_connection(strength, A)
+    splitting = split_nodes(CF, S)
+    P = direct_interpolation(A, S, splitting)
+end

src/multilevel.jl

@@ -0,0 +1,3 @@
+struct Level{Ti,Tv}
+    A::SparseMatrixCSC{Ti,Tv}
+end

src/splitting.jl

@@ -2,7 +2,11 @@ const F_NODE = 0
 const C_NODE = 1
 const U_NODE = 2
 
-function RS(S::SparseMatrixCSC)
+struct RS
+end
+
+split_nodes(::RS, S::SparseMatrixCSC) = RS_CF_splitting(S - spdiagm(diag(S)))
+function RS_CF_splitting(S::SparseMatrixCSC)
 
 	m,n = size(S)
 

src/strength.jl

@@ -1,5 +1,11 @@
-function classical(A::SparseMatrixCSC, θ::Float64)
+abstract type Strength end
+struct Classical{T} <: Strength
+    θ::T
+end
+
+function strength_of_connection{T}(c::Classical{T}, A::SparseMatrixCSC)
 
+    θ = c.θ
     I = Int[]
     J = Int[]
     V = Float64[]

test/runtests.jl

@@ -3,18 +3,18 @@ using Base.Test
 
 # classical strength of connection
 A = poisson(5)
-@test full(classical(A, 0.2)) == [ 1.0  0.5  0.0  0.0  0.0
-                                   0.5  1.0  0.5  0.0  0.0
-                                   0.0  0.5  1.0  0.5  0.0
-                                   0.0  0.0  0.5  1.0  0.5
-                                   0.0  0.0  0.0  0.5  1.0 ]
+X = strength_of_connection(Classical(0.2), A)
+@test full(X) == [ 1.0  0.5  0.0  0.0  0.0
+                   0.5  1.0  0.5  0.0  0.0
+                   0.0  0.5  1.0  0.5  0.0
+                   0.0  0.0  0.5  1.0  0.5
+                   0.0  0.0  0.0  0.5  1.0 ]
 
 # Ruge-Stuben splitting
 S = poisson(7)
-S = S - spdiagm(diag(S)) #FIXME
-@test RS(S) == [0, 1, 0, 1, 0, 1, 0]
+# S = S - spdiagm(diag(S)) #FIXME
+@test split_nodes(RS(), S) == [0, 1, 0, 1, 0, 1, 0]
 
 srand(0)
 S = sprand(10,10,0.1); S = S + S'
-S = S - spdiagm(diag(S))
-@test RS(S) ==  [0, 1, 1, 0, 0, 0, 0, 0, 1, 1]
+@test split_nodes(RS(), S) ==  [0, 1, 1, 0, 0, 0, 0, 0, 1, 1]