From b4b6bd22fa9aae8926c13c71d371df8769e8c88b Mon Sep 17 00:00:00 2001
From: Antonin Portelli <antonin.portelli@me.com>
Date: Tue, 16 Nov 2021 21:34:25 +0000
Subject: [PATCH] compatible with Minuit2 in ROOT

---
 ci-scripts/install-minuit.sh      | 11 +++++------
 configure.ac                      | 22 ++++++++++++++++++----
 lib/Numerical/MinuitMinimizer.cpp | 14 ++++++++++++++
 3 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/ci-scripts/install-minuit.sh b/ci-scripts/install-minuit.sh
index 3c15118..0f6c716 100755
--- a/ci-scripts/install-minuit.sh
+++ b/ci-scripts/install-minuit.sh
@@ -1,6 +1,5 @@
 #!/usr/bin/env bash
 
-NAME='Minuit2-5.34.14'
 
 if (( $# != 1 )); then
   echo "usage: `basename $0` <prefix>" 1>&2
@@ -14,11 +13,11 @@ mkdir -p ${PREFIX}
 cd ${PREFIX}
 PREFIX=$(pwd -P)
 cd ${INITDIR}/local/build
-wget http://www.cern.ch/mathlibs/sw/5_34_14/Minuit2/${NAME}.tar.gz
-tar -xzvf ${NAME}.tar.gz
-mkdir -p ${NAME}/build
-cd ${NAME}/build
-../configure --prefix=${PREFIX} --disable-openmp
+rm -rf root
+git clone https://github.com/root-project/root.git
+cd root/math/minuit2/
+mkdir build; cd build
+cmake .. -Dminuit2_standalone=ON -DCMAKE_INSTALL_PREFIX=${PREFIX}
 make -j4 
 make install
 cd ${INITDIR}/local
diff --git a/configure.ac b/configure.ac
index 17b3aed..d1f2fab 100644
--- a/configure.ac
+++ b/configure.ac
@@ -36,7 +36,7 @@ AC_ARG_WITH([gsl],
 AC_ARG_WITH([minuit],
     [AS_HELP_STRING([--with-minuit=prefix],
 		[try this for a non-standard install prefix of the Minuit2 library])],
-    [AM_CXXFLAGS="$AM_CXXFLAGS -I$with_minuit/include"]
+    [AM_CXXFLAGS="$AM_CXXFLAGS -I$with_minuit/include -I$with_minuit/include/Minuit2 -I$with_minuit/include/Fit"]
 	[AM_LDFLAGS="$AM_LDFLAGS -L$with_minuit/lib"])
 AC_ARG_WITH([nlopt],
     [AS_HELP_STRING([--with-nlopt=prefix],
@@ -90,10 +90,10 @@ AC_CHECK_LIB([hdf5_cpp],[H5Fopen],
     [AC_MSG_ERROR([HDF5 library not found])], [-lhdf5])
 SAVED_LDFLAGS=$LDFLAGS
 LDFLAGS="$LDFLAGS -lMinuit2"
-AC_MSG_CHECKING([for ROOT::Minuit2::BasicMinimumError in -lMinuit2]);
+AC_MSG_CHECKING([for ROOT::Minuit2::VariableMetricMinimizer in -lMinuit2]);
 AC_LINK_IFELSE(
-	[AC_LANG_PROGRAM([#include <Minuit2/BasicMinimumError.h>],
-	[ROOT::Minuit2::BasicMinimumError dummy(0)])],
+	[AC_LANG_PROGRAM([#include <Minuit2/VariableMetricMinimizer.h>],
+	[ROOT::Minuit2::VariableMetricMinimizer dummy()])],
 	[LIBS="$LIBS -lMinuit2"]
 	[AC_DEFINE([HAVE_MINUIT2],
 				[1],
@@ -103,6 +103,20 @@ AC_LINK_IFELSE(
 	[have_minuit=false]
     [AC_MSG_RESULT([no])])
 AM_CONDITIONAL([HAVE_MINUIT], [test x$have_minuit = xtrue])
+LDFLAGS="$LDFLAGS -lMinuit2Math"
+AC_MSG_CHECKING([for ROOT::Math::MinimizerOptions in -lMinuit2Math]);
+AC_LINK_IFELSE(
+	[AC_LANG_PROGRAM([#include <Minuit2/Math/MinimizerOptions.h>],
+	[ROOT::Math::MinimizerOptions dummy()])],
+	[LIBS="$LIBS -lMinuit2Math"]
+	[AC_DEFINE([HAVE_MINUIT2MATH],
+				[1],
+				[Define to 1 if you have the `Minuit2Math' library (-lMinuit2Math).])]
+    [have_minuitmath=true]
+	[AC_MSG_RESULT([yes])],
+	[have_minuitmath=false]
+    [AC_MSG_RESULT([no])])
+AM_CONDITIONAL([HAVE_MINUITMATH], [test x$have_minuit = xtrue])
 LDFLAGS=$SAVED_LDFLAGS
 CXXFLAGS=$CXXFLAGS_CPY
 LDFLAGS=$LDFLAGS_CPY
diff --git a/lib/Numerical/MinuitMinimizer.cpp b/lib/Numerical/MinuitMinimizer.cpp
index c01ff19..bab7638 100644
--- a/lib/Numerical/MinuitMinimizer.cpp
+++ b/lib/Numerical/MinuitMinimizer.cpp
@@ -19,6 +19,20 @@
 
 #include <LatAnalyze/Numerical/MinuitMinimizer.hpp>
 #include <LatAnalyze/includes.hpp>
+
+// forward declaration necessary in the ROOT-based version of Minuit2
+namespace ROOT
+{
+    namespace Fit
+    {
+        class ParameterSettings;
+    };
+};
+
+// macros necessary in the ROOT-based version of Minuit2
+#define ROOT_Math_VecTypes
+#define MATHCORE_STANDALONE
+
 #include <Minuit2/Minuit2Minimizer.h>
 #include <Math/Functor.h>