From 601aa755a4f07a8a08397e79cc24fce70ee06205 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fabian=20Fr=C3=B6hlich?= <fabian@schaluck.com>
Date: Fri, 17 May 2024 14:01:57 +0100
Subject: [PATCH] prototype implementation

---
 include/amici/backwardproblem.h | 6 ++++++
 include/amici/edata.h           | 6 ++++++
 src/edata.cpp                   | 5 +++++
 3 files changed, 17 insertions(+)

diff --git a/include/amici/backwardproblem.h b/include/amici/backwardproblem.h
index a5d32e3c47..64395e00fe 100644
--- a/include/amici/backwardproblem.h
+++ b/include/amici/backwardproblem.h
@@ -70,6 +70,12 @@ class BackwardProblem {
      */
     AmiVector const& getAdjointState() const { return xB_; }
 
+    /**
+     * @brief Accessor for dxB
+     * @return xB
+     */
+    AmiVector const& getAdjointStateDerivative() const { return dxB_; }
+
     /**
      * @brief Accessor for xQB
      * @return xQB
diff --git a/include/amici/edata.h b/include/amici/edata.h
index e135bedd9e..3d7433b1ec 100644
--- a/include/amici/edata.h
+++ b/include/amici/edata.h
@@ -445,6 +445,12 @@ class ExpData : public SimulationParameters {
         std::vector<realtype> const& input, char const* fieldname
     ) const;
 
+    /**
+     * @brief check whether this instance implements only equilibration
+     * without simulation
+     */
+    bool isEquilibration() const;
+
     /** @brief number of observables */
     int nytrue_{0};
 
diff --git a/src/edata.cpp b/src/edata.cpp
index fee49d5717..3bb0a062fc 100644
--- a/src/edata.cpp
+++ b/src/edata.cpp
@@ -386,6 +386,11 @@ void ExpData::checkEventsDimension(
         );
 }
 
+bool ExpData::isEquilibration() const {
+    return ts_.size() == 1 && std::isinf(ts_[0]);
+}
+
+
 void checkSigmaPositivity(
     std::vector<realtype> const& sigmaVector, char const* vectorName
 ) {