feat(composition): added ability to change composition modes

src/composition/private/composition.cpp

@@ -459,4 +459,25 @@ Composition Composition::subset(const std::vector<std::string>& symbols, std::st
         }
     }
     return subsetComposition;
+}
+
+void Composition::setCompositionMode(bool massFracMode) {
+    if (!m_finalized) {
+        LOG_ERROR(m_logger, "Composition has not been finalized. Mode cannot be set unless composition is finalized.");
+        throw std::runtime_error("Composition has not been finalized (Consider running .finalize()). The mode cannot be set unless the composition is finalized.");
+    }
+
+    bool okay = true;
+    for (auto& [_, entry] : m_compositions) {
+        if (massFracMode) {
+            okay = entry.setMassFracMode(m_meanParticleMass);
+        } else {
+            okay = entry.setNumberFracMode(m_specificNumberDensity);
+        }
+        if (!okay) {
+            LOG_ERROR(m_logger, "Composition mode could not be set.");
+            throw std::runtime_error("Composition mode could not be set.");
+        }
+    }
+    m_massFracMode = massFracMode;
 }

src/composition/public/composition.h

@@ -403,6 +403,12 @@ namespace composition{
          */
         Composition subset(const std::vector<std::string>& symbols, std::string method="norm") const;
 
+        /**
+        * @brief Sets the composition mode.
+        * @param massFracMode True if mass fraction mode, false if number fraction mode.
+        */
+        void setCompositionMode(bool massFracMode);
+
         /**
          * @brief Overloaded output stream operator for Composition.
          * @param os The output stream.