Merge pull request #34 from ranjanan/kw

Clean up `solve` API

Author: ranjanan

src/multilevel.jl

@@ -60,12 +60,31 @@ abstract type Cycle end
 struct V <: Cycle
 end
 
+"""
+    solve(ml::MultiLevel, b::Vector, cycle, kwargs...)
+
+Execute multigrid cycling.
+
+Arguments
+=========
+* ml::MultiLevel - the multigrid hierarchy
+* b::Vector - the right hand side
+* cycle -  multigird cycle to execute at each iteration. Defaults to AMG.V()
+
+Keyword Arguments
+=================
+* tol::Float64 - tolerance criteria for convergence
+* maxiter::Int64 - maximum number of iterations to execute
+* verbose::Bool - display residual at each iteration
+* log::Bool - return vector of residuals along with solution
+
+"""
 function solve{T}(ml::MultiLevel, b::Vector{T},
-                                    maxiter = 100,
-                                    cycle = V(),
-                                    tol = 1e-5;
-                                    verbose = false,
-                                    log = false)
+                                    cycle::Cycle = V();
+                                    maxiter::Int = 100,
+                                    tol::Float64 = 1e-5,
+                                    verbose::Bool = false,
+                                    log::Bool = false)
 
     A = length(ml) == 1 ? ml.final_A : ml.levels[1].A                                   
     V = promote_type(eltype(A), eltype(b))

src/preconditioner.jl

@@ -6,7 +6,7 @@ end
 
 aspreconditioner(ml::MultiLevel) = Preconditioner(ml)
 
-\(p::Preconditioner, b) = solve(p.ml, b, 1, V(), 1e-12)
+\(p::Preconditioner, b) = solve(p.ml, b, maxiter = 1, tol = 1e-12)
 *(p::Preconditioner, b) = p.ml.levels[1].A * x
 
 A_ldiv_B!(x, p::Preconditioner, b) = copy!(x, p \ b)

test/runtests.jl

@@ -146,7 +146,7 @@ p = aspreconditioner(ml)
 b = zeros(n)
 b[1] = 1
 b[2] = -1
-x = solve(p.ml, A * ones(n), 1, V(), 1e-12)
+x = solve(p.ml, A * ones(n), maxiter = 1, tol = 1e-12)
 diff = x - [  1.88664780e-16,   2.34982727e-16,   2.33917697e-16,
          8.77869044e-17,   7.16783490e-17,   1.43415460e-16,
          3.69199021e-17,   9.70950385e-17,   4.77034895e-17,
@@ -164,7 +164,7 @@ diff = x - [  1.88664780e-16,   2.34982727e-16,   2.33917697e-16,
         -6.76965535e-16,  -7.00643227e-16,  -6.23581397e-16,
         -7.03016682e-16]
 @test sum(abs2, diff) < 1e-8
-x = solve(p.ml, b, 1, V(), 1e-12)
+x = solve(p.ml, b, maxiter = 1, tol = 1e-12)
 diff = x - [ 0.76347046, -0.5498286 , -0.2705487 , -0.15047352, -0.10248021,
         0.60292674, -0.11497073, -0.08460548, -0.06931461,  0.38230708,
        -0.055664  , -0.04854558, -0.04577031,  0.09964325,  0.01825624,
@@ -205,7 +205,7 @@ diff = x - [0.823762, -0.537478, -0.306212, -0.19359, -0.147621, 0.685002,
             0.0511691, 0.0502043, 0.0498349, 0.0498134]
 @test sum(abs2, diff) < 1e-8
 
-x = solve(ml, b, 1, V(), 1e-12)
+x = solve(ml, b, maxiter = 1, tol = 1e-12)
 diff = x - [0.775725, -0.571202, -0.290989, -0.157001, -0.106981, 0.622652,
             -0.122318, -0.0891874, -0.0709834, 0.392621, -0.055544, -0.0507485,
             -0.0466376, 0.107175, 0.0267468, -0.0200843, -0.0282827, -0.0299929,