From 635a4827754cdf4d6530b6edf864d67559a4cb2b Mon Sep 17 00:00:00 2001
From: Alexander Voigt <Alexander.Voigt@desy.de>
Date: Sat, 18 Jul 2015 15:48:59 +0200
Subject: [PATCH] try all root-finding algorithms

---
 src/root_solver.cpp | 11 +++--------
 src/root_solver.hpp |  6 ++----
 2 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/src/root_solver.cpp b/src/root_solver.cpp
index 918817d3e..d5d288ebc 100644
--- a/src/root_solver.cpp
+++ b/src/root_solver.cpp
@@ -89,16 +89,11 @@ void RGFlow<Root>::solve()
    if (models.empty() || max_iterations == 0)
       return;
 
-   // try the following algorithms
-   ERootFinder_t algorithms[] = { Hybrid// , HybridS
-   };
-
    int status = GSL_CONTINUE;
 
-   initial_guess();
-
-   for (unsigned i = 0; i < sizeof(algorithms)/sizeof(*algorithms)
-           && status != GSL_SUCCESS; i++) {
+   for (unsigned i = 0; i < NUMBER_OF_ROOT_FINDERS && status != GSL_SUCCESS;
+        i++) {
+      initial_guess();
       status = find_root(static_cast<ERootFinder_t>(i));
    }
 
diff --git a/src/root_solver.hpp b/src/root_solver.hpp
index c0809b834..29afb2b4a 100644
--- a/src/root_solver.hpp
+++ b/src/root_solver.hpp
@@ -56,10 +56,8 @@ template<>
 class RGFlow<Root> {
 public:
 
-   /// Note: The Newton and Broyden algorithms will not work if some
-   /// model parameters are identically zero, as this will lead to a
-   /// non-invertible Jakobian matrix.
-   enum ERootFinder_t { Hybrid, HybridS, Broyden, Newton };
+   enum ERootFinder_t { Hybrid, HybridS, Broyden, Newton,
+                        NUMBER_OF_ROOT_FINDERS };
 
    RGFlow();
    ~RGFlow();