From 55bda99415d1e5f39552b80ef020f1ac70985755 Mon Sep 17 00:00:00 2001
From: HenrZu <69154294+HenrZu@users.noreply.github.com>
Date: Fri, 13 Dec 2024 10:47:12 +0100
Subject: [PATCH 1/7] divi io model independent, get_region_id also

---
 cpp/memilio/CMakeLists.txt                |   1 +
 cpp/memilio/io/parameters_io.h            | 120 ++++++++++++++++++++++
 cpp/models/ode_secir/parameters_io.cpp    |  42 +-------
 cpp/models/ode_secir/parameters_io.h      |  11 +-
 cpp/models/ode_secirts/parameters_io.h    |  90 +---------------
 cpp/models/ode_secirvvs/parameters_io.cpp |  47 ---------
 cpp/models/ode_secirvvs/parameters_io.h   |  16 +--
 7 files changed, 125 insertions(+), 202 deletions(-)
 create mode 100644 cpp/memilio/io/parameters_io.h

diff --git a/cpp/memilio/CMakeLists.txt b/cpp/memilio/CMakeLists.txt
index e8b58aded5..ab8fea25fc 100644
--- a/cpp/memilio/CMakeLists.txt
+++ b/cpp/memilio/CMakeLists.txt
@@ -39,6 +39,7 @@ add_library(memilio
     io/history.h
     io/mobility_io.h
     io/mobility_io.cpp
+    io/parameters_io.h
     io/result_io.h
     io/result_io.cpp
     io/epi_data.h
diff --git a/cpp/memilio/io/parameters_io.h b/cpp/memilio/io/parameters_io.h
new file mode 100644
index 0000000000..ad895e6183
--- /dev/null
+++ b/cpp/memilio/io/parameters_io.h
@@ -0,0 +1,120 @@
+/* 
+* Copyright (C) 2020-2024 MEmilio
+*
+* Authors: Henrik Zunker
+*
+* Contact: Martin J. Kuehn <Martin.Kuehn@DLR.de>
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*     http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+#ifndef MEMILIO_IO_PARAMETER_H
+#define MEMILIO_IO_PARAMETER_H
+
+#include "memilio/config.h"
+
+#ifdef MEMILIO_HAS_JSONCPP
+
+#include "memilio/io/epi_data.h"
+#include "memilio/io/result_io.h"
+#include "json/value.h"
+#include <string>
+#include <vector>
+
+namespace mio
+{
+/**
+ * @brief Gets the region ID (county, state, or district) of an EpiDataEntry.
+ * 
+ * If none are available, it defaults to 0 which is representing the whole country.
+ * 
+ * @tparam EpiDataEntry The type of the data entry.
+ * @param data_entry The (RKI) data entry to extract the region ID from.
+ * @return The region ID as integer, or 0 if no specific region information is available.
+ */
+template <class EpiDataEntry>
+int get_region_id(const EpiDataEntry& data_entry)
+{
+    return data_entry.county_id ? data_entry.county_id->get()
+                                : (data_entry.state_id ? data_entry.state_id->get()
+                                                       : (data_entry.district_id ? data_entry.district_id->get() : 0));
+}
+
+/**
+ * @brief Extracts the number of individuals in critical condition (ICU) for each region 
+ * on a specified date from the provided DIVI data.
+ *
+ * @tparam FP Floating point type (default: double).
+ *
+ * @param[in] divi_data Vector of DIVI data entries containing date, region, and ICU information.
+ * @param[in] vregion Vector of region IDs for which the data is computed.
+ * @param[in] date Date for which the ICU data is computed.
+ * @param[out] vnum_icu Output vector containing the number of ICU cases for each region.
+ *
+ * @return An IOResult indicating success or failure.
+ */
+template <typename FP = double>
+IOResult<void> compute_divi_data(const std::vector<DiviEntry>& divi_data, const std::vector<int>& vregion, Date date,
+                                 std::vector<FP>& vnum_icu)
+{
+    auto max_date_entry = std::max_element(divi_data.begin(), divi_data.end(), [](auto&& a, auto&& b) {
+        return a.date < b.date;
+    });
+    if (max_date_entry == divi_data.end()) {
+        log_error("DIVI data is empty.");
+        return failure(StatusCode::InvalidValue, "DIVI data is empty.");
+    }
+    auto max_date = max_date_entry->date;
+    if (max_date < date) {
+        log_error("DIVI data does not contain the specified date.");
+        return failure(StatusCode::OutOfRange, "DIVI data does not contain the specified date.");
+    }
+
+    for (auto&& entry : divi_data) {
+        auto it      = std::find_if(vregion.begin(), vregion.end(), [&entry](auto r) {
+            return r == 0 || r == get_region_id(entry);
+        });
+        auto date_df = entry.date;
+        if (it != vregion.end() && date_df == date) {
+            auto region_idx      = size_t(it - vregion.begin());
+            vnum_icu[region_idx] = entry.num_icu;
+        }
+    }
+
+    return success();
+}
+
+/**
+ * @brief Reads DIVI data from a file and computes the ICU data for specified regions and date.
+ *
+ * @tparam FP Floating point type (default: double).
+ *
+ * @param[in] path Path to the file containing DIVI data.
+ * @param[in] vregion Vector of region IDs for which the data is computed.
+ * @param[in] date Date for which the ICU data is computed.
+ * @param[out] vnum_icu Output vector containing the number of ICU cases for each region.
+ *
+ * @return An IOResult indicating success or failure.
+ */
+template <typename FP = double>
+IOResult<void> read_divi_data(const std::string& path, const std::vector<int>& vregion, Date date,
+                              std::vector<FP>& vnum_icu)
+{
+    BOOST_OUTCOME_TRY(auto&& divi_data, mio::read_divi_data(path));
+    return compute_divi_data(divi_data, vregion, date, vnum_icu);
+}
+
+} // namespace mio
+
+#endif //MEMILIO_HAS_JSONCPP
+
+#endif //MEMILIO_IO_PARAMETER_H
diff --git a/cpp/models/ode_secir/parameters_io.cpp b/cpp/models/ode_secir/parameters_io.cpp
index 68923adb90..47f45b0ef8 100644
--- a/cpp/models/ode_secir/parameters_io.cpp
+++ b/cpp/models/ode_secir/parameters_io.cpp
@@ -30,6 +30,7 @@ GCC_CLANG_DIAGNOSTIC(ignored "-Wmaybe-uninitialized")
 
 #include "ode_secir/parameters_io.h"
 #include "memilio/io/epi_data.h"
+#include "memilio/io/parameters_io.h"
 #include "memilio/io/io.h"
 #include "memilio/utils/stl_util.h"
 #include "memilio/utils/date.h"
@@ -42,15 +43,6 @@ namespace osecir
 
 namespace details
 {
-//district, county or state id of a data entry if available, 0 (for whole country) otherwise
-//used to compare data entries to integer ids in STL algorithms
-template <class EpiDataEntry>
-int get_region_id(const EpiDataEntry& entry)
-{
-    return entry.county_id
-               ? entry.county_id->get()
-               : (entry.state_id ? entry.state_id->get() : (entry.district_id ? entry.district_id->get() : 0));
-}
 //overload for integers, so the comparison of data entry to integers is symmetric (required by e.g. equal_range)
 int get_region_id(int id)
 {
@@ -201,38 +193,6 @@ IOResult<void> read_confirmed_cases_data(
     return success();
 }
 
-IOResult<void> read_divi_data(const std::string& path, const std::vector<int>& vregion, Date date,
-                              std::vector<double>& vnum_icu)
-{
-    BOOST_OUTCOME_TRY(auto&& divi_data, mio::read_divi_data(path));
-
-    auto max_date_entry = std::max_element(divi_data.begin(), divi_data.end(), [](auto&& a, auto&& b) {
-        return a.date < b.date;
-    });
-    if (max_date_entry == divi_data.end()) {
-        log_error("DIVI data file is empty.");
-        return failure(StatusCode::InvalidFileFormat, path + ", file is empty.");
-    }
-    auto max_date = max_date_entry->date;
-    if (max_date < date) {
-        log_error("Specified date does not exist in DIVI data.");
-        return failure(StatusCode::OutOfRange, path + ", specified date does not exist in DIVI data.");
-    }
-
-    for (auto&& entry : divi_data) {
-        auto it      = std::find_if(vregion.begin(), vregion.end(), [&entry](auto r) {
-            return r == 0 || r == get_region_id(entry);
-        });
-        auto date_df = entry.date;
-        if (it != vregion.end() && date_df == date) {
-            auto region_idx      = size_t(it - vregion.begin());
-            vnum_icu[region_idx] = entry.num_icu;
-        }
-    }
-
-    return success();
-}
-
 IOResult<std::vector<std::vector<double>>>
 read_population_data(const std::string& path, const std::vector<int>& vregion, bool accumulate_age_groups)
 {
diff --git a/cpp/models/ode_secir/parameters_io.h b/cpp/models/ode_secir/parameters_io.h
index 7713232ce4..659ca49e7d 100644
--- a/cpp/models/ode_secir/parameters_io.h
+++ b/cpp/models/ode_secir/parameters_io.h
@@ -27,6 +27,7 @@
 
 #include "ode_secir/model.h"
 #include "memilio/io/epi_data.h"
+#include "memilio/io/parameters_io.h"
 #include "memilio/io/result_io.h"
 
 namespace mio
@@ -167,16 +168,6 @@ IOResult<void> set_confirmed_cases_data(std::vector<Model<FP>>& model, const std
     return success();
 }
 
-/**
-     * @brief Reads number of ICU patients from DIVI register into Parameters.
-     * @param[in] path Path to DIVI file.
-     * @param[in] vregion Keys of the region of interest.
-     * @param date Date for which we initialize.
-     * @param vnum_icu Number of ICU patients.
-     */
-IOResult<void> read_divi_data(const std::string& path, const std::vector<int>& vregion, Date date,
-                              std::vector<double>& vnum_icu);
-
 /**
      * @brief Sets populations data from DIVI register into Model.
      * @tparam FP floating point data type, e.g., double.
diff --git a/cpp/models/ode_secirts/parameters_io.h b/cpp/models/ode_secirts/parameters_io.h
index a4c7028483..dd699e841f 100644
--- a/cpp/models/ode_secirts/parameters_io.h
+++ b/cpp/models/ode_secirts/parameters_io.h
@@ -30,6 +30,7 @@
 #include "memilio/mobility/graph.h"
 #include "memilio/mobility/metapopulation_mobility_instant.h"
 #include "memilio/io/epi_data.h"
+#include "memilio/io/parameters_io.h"
 #include "memilio/io/io.h"
 #include "memilio/io/json_serializer.h"
 #include "memilio/io/result_io.h"
@@ -43,31 +44,6 @@ namespace osecirts
 
 namespace details
 {
-
-/**
- * @brief Gets the region ID (county, state, or district) of an EpiDataEntry.
- * 
- * If none are available, it defaults to 0 which is representing the whole country.
- * 
- * @tparam EpiDataEntry The type of the data entry.
- * @param data_entry The (RKI) data entry to extract the region ID from.
- * @return The region ID as integer, or 0 if no specific region information is available.
- */
-template <class EpiDataEntry>
-int get_region_id(const EpiDataEntry& data_entry)
-{
-    if (data_entry.county_id) {
-        return data_entry.county_id->get();
-    }
-    if (data_entry.state_id) {
-        return data_entry.state_id->get();
-    }
-    if (data_entry.district_id) {
-        return data_entry.district_id->get();
-    }
-    return 0;
-}
-
 /**
  * @brief Computes the distribution of confirmed cases across infection states based on Case (RKI) data.
  *
@@ -558,70 +534,6 @@ IOResult<void> set_confirmed_cases_data(std::vector<Model>& model, const std::st
     return success();
 }
 
-/**
- * @brief Extracts the number of individuals in critical condition (ICU) for each region 
- * on a specified date from the provided DIVI data.
- *
- * @tparam FP Floating point type (default: double).
- *
- * @param[in] divi_data Vector of DIVI data entries containing date, region, and ICU information.
- * @param[in] vregion Vector of region IDs for which the data is computed.
- * @param[in] date Date for which the ICU data is computed.
- * @param[out] vnum_icu Output vector containing the number of ICU cases for each region.
- *
- * @return An IOResult indicating success or failure.
- */
-template <typename FP = double>
-IOResult<void> compute_divi_data(const std::vector<DiviEntry>& divi_data, const std::vector<int>& vregion, Date date,
-                                 std::vector<FP>& vnum_icu)
-{
-    auto max_date_entry = std::max_element(divi_data.begin(), divi_data.end(), [](auto&& a, auto&& b) {
-        return a.date < b.date;
-    });
-    if (max_date_entry == divi_data.end()) {
-        log_error("DIVI data is empty.");
-        return failure(StatusCode::InvalidValue, "DIVI data is empty.");
-    }
-    auto max_date = max_date_entry->date;
-    if (max_date < date) {
-        log_error("DIVI data does not contain the specified date.");
-        return failure(StatusCode::OutOfRange, "DIVI data does not contain the specified date.");
-    }
-
-    for (auto&& entry : divi_data) {
-        auto it      = std::find_if(vregion.begin(), vregion.end(), [&entry](auto r) {
-            return r == 0 || r == get_region_id(entry);
-        });
-        auto date_df = entry.date;
-        if (it != vregion.end() && date_df == date) {
-            auto region_idx      = size_t(it - vregion.begin());
-            vnum_icu[region_idx] = entry.num_icu;
-        }
-    }
-
-    return success();
-}
-
-/**
- * @brief Reads DIVI data from a file and computes the ICU data for specified regions and date.
- *
- * @tparam FP Floating point type (default: double).
- *
- * @param[in] path Path to the file containing DIVI data.
- * @param[in] vregion Vector of region IDs for which the data is computed.
- * @param[in] date Date for which the ICU data is computed.
- * @param[out] vnum_icu Output vector containing the number of ICU cases for each region.
- *
- * @return An IOResult indicating success or failure.
- */
-template <typename FP = double>
-IOResult<void> read_divi_data(const std::string& path, const std::vector<int>& vregion, Date date,
-                              std::vector<FP>& vnum_icu)
-{
-    BOOST_OUTCOME_TRY(auto&& divi_data, mio::read_divi_data(path));
-    return compute_divi_data(divi_data, vregion, date, vnum_icu);
-}
-
 /**
  * @brief Sets ICU data from DIVI data into the a vector of models, distributed across age groups.
  *
diff --git a/cpp/models/ode_secirvvs/parameters_io.cpp b/cpp/models/ode_secirvvs/parameters_io.cpp
index 35e6903064..7daea0f392 100644
--- a/cpp/models/ode_secirvvs/parameters_io.cpp
+++ b/cpp/models/ode_secirvvs/parameters_io.cpp
@@ -29,16 +29,6 @@ namespace osecirvvs
 {
 namespace details
 {
-//gets the county or state id of the entry if available, 0 (for whole country) otherwise
-//used for comparisons of entry to integer region id
-template <class EpiDataEntry>
-int get_region_id(const EpiDataEntry& rki_entry)
-{
-    return rki_entry.county_id ? rki_entry.county_id->get()
-                               : (rki_entry.state_id ? rki_entry.state_id->get()
-                                                     : (rki_entry.district_id ? rki_entry.district_id->get() : 0));
-}
-
 IOResult<void> read_confirmed_cases_data(
     std::string const& path, std::vector<int> const& vregion, Date date, std::vector<std::vector<double>>& vnum_Exposed,
     std::vector<std::vector<double>>& vnum_InfectedNoSymptoms, std::vector<std::vector<double>>& vnum_InfectedSymptoms,
@@ -279,43 +269,6 @@ IOResult<void> read_confirmed_cases_data_fix_recovered(const std::vector<Confirm
     return success();
 }
 
-IOResult<void> read_divi_data(const std::string& path, const std::vector<int>& vregion, Date date,
-                              std::vector<double>& vnum_icu)
-{
-    BOOST_OUTCOME_TRY(auto&& divi_data, mio::read_divi_data(path));
-    return read_divi_data(divi_data, vregion, date, vnum_icu);
-}
-
-IOResult<void> read_divi_data(const std::vector<DiviEntry>& divi_data, const std::vector<int>& vregion, Date date,
-                              std::vector<double>& vnum_icu)
-{
-    auto max_date_entry = std::max_element(divi_data.begin(), divi_data.end(), [](auto&& a, auto&& b) {
-        return a.date < b.date;
-    });
-    if (max_date_entry == divi_data.end()) {
-        log_error("DIVI data is empty.");
-        return failure(StatusCode::InvalidValue, "DIVI data is empty.");
-    }
-    auto max_date = max_date_entry->date;
-    if (max_date < date) {
-        log_error("DIVI data does not contain the specified date.");
-        return failure(StatusCode::OutOfRange, "DIVI data does not contain the specified date.");
-    }
-
-    for (auto&& entry : divi_data) {
-        auto it      = std::find_if(vregion.begin(), vregion.end(), [&entry](auto r) {
-            return r == 0 || r == get_region_id(entry);
-        });
-        auto date_df = entry.date;
-        if (it != vregion.end() && date_df == date) {
-            auto region_idx      = size_t(it - vregion.begin());
-            vnum_icu[region_idx] = entry.num_icu;
-        }
-    }
-
-    return success();
-}
-
 IOResult<std::vector<std::vector<double>>> read_population_data(const std::string& path,
                                                                 const std::vector<int>& vregion)
 {
diff --git a/cpp/models/ode_secirvvs/parameters_io.h b/cpp/models/ode_secirvvs/parameters_io.h
index dbf0056d26..f6119fccf1 100644
--- a/cpp/models/ode_secirvvs/parameters_io.h
+++ b/cpp/models/ode_secirvvs/parameters_io.h
@@ -26,6 +26,7 @@
 
 #include "ode_secirvvs/model.h"
 #include "memilio/io/epi_data.h"
+#include "memilio/io/parameters_io.h"
 #include "memilio/io/io.h"
 #include "memilio/io/result_io.h"
 #include "memilio/utils/date.h"
@@ -387,21 +388,6 @@ IOResult<void> set_confirmed_cases_data(std::vector<Model>& model, const std::st
     return success();
 }
 
-/**
-        * @brief reads number of ICU patients from DIVI register into Parameters
-        * @param[in] path Path to transformed DIVI file
-        * @param[in] vregion Keys of the region of interest
-        * @param[in] date Date for which the arrays are initialized
-        * @param[in, out] vnum_icu number of ICU patients
-        * @see mio::read_divi_data
-        * @{
-        */
-IOResult<void> read_divi_data(const std::string& path, const std::vector<int>& vregion, Date date,
-                              std::vector<double>& vnum_icu);
-IOResult<void> read_divi_data(const std::vector<DiviEntry>& divi_data, const std::vector<int>& vregion, Date date,
-                              std::vector<double>& vnum_icu);
-/**@}*/
-
 /**
         * @brief sets populations data from DIVI register into Model
         * @param[in, out] model vector of objects in which the data is set

From a841c9051b18a60e2e2d66a811a330b9b76e57d8 Mon Sep 17 00:00:00 2001
From: HenrZu <69154294+HenrZu@users.noreply.github.com>
Date: Fri, 13 Dec 2024 13:27:05 +0100
Subject: [PATCH 2/7] read population data

---
 cpp/memilio/CMakeLists.txt                |  1 +
 cpp/memilio/io/parameters_io.cpp          | 72 +++++++++++++++++++++++
 cpp/memilio/io/parameters_io.h            | 21 +++++++
 cpp/models/ode_secir/parameters_io.cpp    | 38 ------------
 cpp/models/ode_secir/parameters_io.h      | 16 +----
 cpp/models/ode_secirts/parameters_io.cpp  | 40 -------------
 cpp/models/ode_secirts/parameters_io.h    | 28 +--------
 cpp/models/ode_secirvvs/parameters_io.cpp | 39 ------------
 cpp/models/ode_secirvvs/parameters_io.h   | 17 +-----
 cpp/tests/test_odesecir.cpp               | 20 +------
 cpp/tests/test_odesecirvvs.cpp            | 11 ++--
 11 files changed, 109 insertions(+), 194 deletions(-)
 create mode 100644 cpp/memilio/io/parameters_io.cpp

diff --git a/cpp/memilio/CMakeLists.txt b/cpp/memilio/CMakeLists.txt
index ab8fea25fc..ffca36d571 100644
--- a/cpp/memilio/CMakeLists.txt
+++ b/cpp/memilio/CMakeLists.txt
@@ -40,6 +40,7 @@ add_library(memilio
     io/mobility_io.h
     io/mobility_io.cpp
     io/parameters_io.h
+    io/parameters_io.cpp
     io/result_io.h
     io/result_io.cpp
     io/epi_data.h
diff --git a/cpp/memilio/io/parameters_io.cpp b/cpp/memilio/io/parameters_io.cpp
new file mode 100644
index 0000000000..a547e1508b
--- /dev/null
+++ b/cpp/memilio/io/parameters_io.cpp
@@ -0,0 +1,72 @@
+/* 
+* Copyright (C) 2020-2024 MEmilio
+*
+* Authors: Henrik Zunker
+*
+* Contact: Martin J. Kuehn <Martin.Kuehn@DLR.de>
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*     http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+#include "memilio/config.h"
+
+#ifdef MEMILIO_HAS_JSONCPP
+
+#include "memilio/io/epi_data.h"
+#include "memilio/io/result_io.h"
+#include "json/value.h"
+#include <string>
+#include <vector>
+
+namespace mio
+{
+IOResult<std::vector<std::vector<double>>> read_population_data(const std::vector<PopulationDataEntry>& population_data,
+                                                                const std::vector<int>& vregion)
+{
+    std::vector<std::vector<double>> vnum_population(
+        vregion.size(), std::vector<double>(ConfirmedCasesDataEntry::age_group_names.size(), 0.0));
+
+    for (auto&& county_entry : population_data) {
+        //accumulate population of states or country from population of counties
+        if (!county_entry.county_id && !county_entry.district_id) {
+            return failure(StatusCode::InvalidFileFormat, "File with county population expected.");
+        }
+        //find region that this county belongs to
+        //all counties belong to the country (id = 0)
+        auto it = std::find_if(vregion.begin(), vregion.end(), [&county_entry](auto r) {
+            return r == 0 ||
+                   (county_entry.county_id &&
+                    regions::StateId(r) == regions::get_state_id(int(*county_entry.county_id))) ||
+                   (county_entry.county_id && regions::CountyId(r) == *county_entry.county_id) ||
+                   (county_entry.district_id && regions::DistrictId(r) == *county_entry.district_id);
+        });
+        if (it != vregion.end()) {
+            auto region_idx      = size_t(it - vregion.begin());
+            auto& num_population = vnum_population[region_idx];
+            for (size_t age = 0; age < num_population.size(); age++) {
+                num_population[age] += county_entry.population[AgeGroup(age)];
+            }
+        }
+    }
+
+    return success(vnum_population);
+}
+
+IOResult<std::vector<std::vector<double>>> read_population_data(const std::string& path,
+                                                                const std::vector<int>& vregion)
+{
+    BOOST_OUTCOME_TRY(auto&& population_data, mio::read_population_data(path));
+    return read_population_data(population_data, vregion);
+}
+} // namespace mio
+#endif //MEMILIO_HAS_JSONCPP
diff --git a/cpp/memilio/io/parameters_io.h b/cpp/memilio/io/parameters_io.h
index ad895e6183..9aedfe6072 100644
--- a/cpp/memilio/io/parameters_io.h
+++ b/cpp/memilio/io/parameters_io.h
@@ -113,6 +113,27 @@ IOResult<void> read_divi_data(const std::string& path, const std::vector<int>& v
     return compute_divi_data(divi_data, vregion, date, vnum_icu);
 }
 
+/**
+ * @brief Reads population data from a vector of population data entries.
+ * 
+ * @param[in] population_data Vector of population data entries.
+ * @param[in] vregion Vector of keys representing the regions of interest.
+ * @return An IOResult containing a vector of vectors, where each inner vector represents the population
+ *         distribution across age groups for a specific region, or an error if the function fails.
+ */
+IOResult<std::vector<std::vector<double>>> read_population_data(const std::vector<PopulationDataEntry>&,
+                                                                const std::vector<int>&);
+
+/**
+ * @brief Reads population data from census data.
+ * 
+ * @param[in] path Path to the population data file.
+ * @param[in] vregion Vector of keys representing the regions of interest.
+ * @return An IOResult containing a vector of vectors, where each inner vector represents the population
+ *         distribution across age groups for a specific region, or an error if the function fails.
+ */
+IOResult<std::vector<std::vector<double>>> read_population_data(const std::string&, const std::vector<int>&);
+
 } // namespace mio
 
 #endif //MEMILIO_HAS_JSONCPP
diff --git a/cpp/models/ode_secir/parameters_io.cpp b/cpp/models/ode_secir/parameters_io.cpp
index 47f45b0ef8..6ac7dc71db 100644
--- a/cpp/models/ode_secir/parameters_io.cpp
+++ b/cpp/models/ode_secir/parameters_io.cpp
@@ -193,44 +193,6 @@ IOResult<void> read_confirmed_cases_data(
     return success();
 }
 
-IOResult<std::vector<std::vector<double>>>
-read_population_data(const std::string& path, const std::vector<int>& vregion, bool accumulate_age_groups)
-{
-    BOOST_OUTCOME_TRY(auto&& population_data, mio::read_population_data(path, !accumulate_age_groups));
-    //if we set up the model for one age group, the population data should be read in with the
-    //age groups given in the population data json file and are accumulated later
-    //otherwise the populations are directly saved for the correct model age groups
-    size_t age_group_size = accumulate_age_groups ? PopulationDataEntry::age_group_names.size()
-                                                  : ConfirmedCasesDataEntry::age_group_names.size();
-    std::vector<std::vector<double>> vnum_population(vregion.size(), std::vector<double>(age_group_size, 0.0));
-
-    for (auto&& entry : population_data) {
-        auto it = std::find_if(vregion.begin(), vregion.end(), [&entry](auto r) {
-            return r == 0 || (entry.county_id && regions::StateId(r) == regions::get_state_id(int(*entry.county_id))) ||
-                   (entry.county_id && regions::CountyId(r) == *entry.county_id) ||
-                   (entry.district_id && regions::DistrictId(r) == *entry.district_id);
-        });
-        if (it != vregion.end()) {
-            auto region_idx      = size_t(it - vregion.begin());
-            auto& num_population = vnum_population[region_idx];
-            for (size_t age = 0; age < num_population.size(); age++) {
-                num_population[age] += entry.population[AgeGroup(age)];
-            }
-        }
-    }
-    if (accumulate_age_groups) {
-        std::vector<std::vector<double>> vnum_pop_acc(vregion.size(), std::vector<double>(1, 0));
-        for (size_t region = 0; region < vregion.size(); ++region) {
-            vnum_pop_acc[region][0] =
-                std::accumulate(vnum_population[region].begin(), vnum_population[region].end(), 0.0);
-        }
-        return success(vnum_pop_acc);
-    }
-    else {
-        return success(vnum_population);
-    }
-}
-
 } // namespace details
 } // namespace osecir
 } // namespace mio
diff --git a/cpp/models/ode_secir/parameters_io.h b/cpp/models/ode_secir/parameters_io.h
index 659ca49e7d..e47c49efcf 100644
--- a/cpp/models/ode_secir/parameters_io.h
+++ b/cpp/models/ode_secir/parameters_io.h
@@ -206,16 +206,6 @@ IOResult<void> set_divi_data(std::vector<Model<FP>>& model, const std::string& p
     return success();
 }
 
-/**
-     * @brief Reads population data from census data.
-     * @tparam FP floating point data type, e.g., double.
-     * @param[in] path Path to RKI file.
-     * @param[in] vregion Vector of keys of the regions of interest. 
-     * @param[in] accumulate_age_groups Specifies whether population data should be accumulated to one age group.
-     */
-IOResult<std::vector<std::vector<double>>>
-read_population_data(const std::string& path, const std::vector<int>& vregion, bool accumulate_age_groups = false);
-
 /**
 * @brief Sets population data from census data which has been read into num_population.
 * @tparam FP floating point data type, e.g., double.
@@ -251,9 +241,7 @@ template <typename FP = double>
 IOResult<void> set_population_data(std::vector<Model<FP>>& model, const std::string& path,
                                    const std::vector<int>& vregion)
 {
-    // Specifies whether population data should be accumulated to one age group.
-    const bool is_single_age_group = static_cast<size_t>(model[0].parameters.get_num_groups()) == 1;
-    BOOST_OUTCOME_TRY(const auto&& num_population, read_population_data(path, vregion, is_single_age_group));
+    BOOST_OUTCOME_TRY(const auto&& num_population, read_population_data(path, vregion));
     BOOST_OUTCOME_TRY(set_population_data(model, num_population, vregion));
     return success();
 }
@@ -291,7 +279,7 @@ IOResult<void> export_input_data_county_timeseries(
     std::vector<TimeSeries<double>> extrapolated_data(
         region.size(), TimeSeries<double>::zero(num_days + 1, (size_t)InfectionState::Count * num_age_groups));
 
-    BOOST_OUTCOME_TRY(auto&& num_population, details::read_population_data(population_data_path, region));
+    BOOST_OUTCOME_TRY(auto&& num_population, mio::read_population_data(population_data_path, region));
     BOOST_OUTCOME_TRY(auto&& case_data, mio::read_confirmed_cases_data(confirmed_cases_path));
 
     for (int t = 0; t <= num_days; ++t) {
diff --git a/cpp/models/ode_secirts/parameters_io.cpp b/cpp/models/ode_secirts/parameters_io.cpp
index 4f25fee0b3..fb80842365 100644
--- a/cpp/models/ode_secirts/parameters_io.cpp
+++ b/cpp/models/ode_secirts/parameters_io.cpp
@@ -52,46 +52,6 @@ namespace osecirts
 {
 namespace details
 {
-
-IOResult<std::vector<std::vector<double>>> read_population_data(const std::string& path,
-                                                                const std::vector<int>& vregion)
-{
-    BOOST_OUTCOME_TRY(auto&& population_data, mio::read_population_data(path));
-    return read_population_data(population_data, vregion);
-}
-
-IOResult<std::vector<std::vector<double>>> read_population_data(const std::vector<PopulationDataEntry>& population_data,
-                                                                const std::vector<int>& vregion)
-{
-    std::vector<std::vector<double>> vnum_population(
-        vregion.size(), std::vector<double>(ConfirmedCasesDataEntry::age_group_names.size(), 0.0));
-
-    for (auto&& county_entry : population_data) {
-        //accumulate population of states or country from population of counties
-        if (!county_entry.county_id && !county_entry.district_id) {
-            return failure(StatusCode::InvalidFileFormat, "File with county population expected.");
-        }
-        //find region that this county belongs to
-        //all counties belong to the country (id = 0)
-        auto it = std::find_if(vregion.begin(), vregion.end(), [&county_entry](auto r) {
-            return r == 0 ||
-                   (county_entry.county_id &&
-                    regions::StateId(r) == regions::get_state_id(int(*county_entry.county_id))) ||
-                   (county_entry.county_id && regions::CountyId(r) == *county_entry.county_id) ||
-                   (county_entry.district_id && regions::DistrictId(r) == *county_entry.district_id);
-        });
-        if (it != vregion.end()) {
-            auto region_idx      = size_t(it - vregion.begin());
-            auto& num_population = vnum_population[region_idx];
-            for (size_t age = 0; age < num_population.size(); age++) {
-                num_population[age] += county_entry.population[AgeGroup(age)];
-            }
-        }
-    }
-
-    return success(vnum_population);
-}
-
 } // namespace details
 } // namespace osecirts
 } // namespace mio
diff --git a/cpp/models/ode_secirts/parameters_io.h b/cpp/models/ode_secirts/parameters_io.h
index dd699e841f..3b6834aa9e 100644
--- a/cpp/models/ode_secirts/parameters_io.h
+++ b/cpp/models/ode_secirts/parameters_io.h
@@ -581,30 +581,6 @@ IOResult<void> set_divi_data(std::vector<Model>& model, const std::string& path,
     return success();
 }
 
-/**
- * @brief Reads population data from census data.
- * 
- * @param[in] path Path to the population data file.
- * @param[in] vregion Vector of keys representing the regions of interest.
- * @return An IOResult containing a vector of vectors, where each inner vector represents the population
- *         distribution across age groups for a specific region, or an error if the function fails.
- * @see mio::read_population_data
- */
-IOResult<std::vector<std::vector<double>>> read_population_data(const std::string& path,
-                                                                const std::vector<int>& vregion);
-
-/**
- * @brief Reads population data from a vector of population data entries.
- * 
- * @param[in] population_data Vector of population data entries.
- * @param[in] vregion Vector of keys representing the regions of interest.
- * @return An IOResult containing a vector of vectors, where each inner vector represents the population
- *         distribution across age groups for a specific region, or an error if the function fails.
- * @see mio::read_population_data
- */
-IOResult<std::vector<std::vector<double>>> read_population_data(const std::vector<PopulationDataEntry>& population_data,
-                                                                const std::vector<int>& vregion);
-
 /**
  * @brief Sets the population data for the given models based on the provided population distribution and immunity levels.
  *
@@ -697,7 +673,7 @@ template <class Model>
 IOResult<void> set_population_data(std::vector<Model>& model, const std::string& path, const std::vector<int>& vregion,
                                    const std::vector<std::vector<double>> immunity_population)
 {
-    BOOST_OUTCOME_TRY(auto&& num_population, details::read_population_data(path, vregion));
+    BOOST_OUTCOME_TRY(auto&& num_population, mio::read_population_data(path, vregion));
     BOOST_OUTCOME_TRY(set_population_data(model, num_population, vregion, immunity_population));
     return success();
 }
@@ -888,7 +864,7 @@ IOResult<void> export_input_data_county_timeseries(
         models.size(), TimeSeries<double>::zero(num_days + 1, (size_t)InfectionState::Count * num_groups));
 
     BOOST_OUTCOME_TRY(auto&& case_data, read_confirmed_cases_data(confirmed_cases_path));
-    BOOST_OUTCOME_TRY(auto&& population_data, details::read_population_data(population_data_path, counties));
+    BOOST_OUTCOME_TRY(auto&& population_data, read_population_data(population_data_path, counties));
 
     // empty vector if set_vaccination_data is not set
     std::vector<VaccinationDataEntry> vacc_data;
diff --git a/cpp/models/ode_secirvvs/parameters_io.cpp b/cpp/models/ode_secirvvs/parameters_io.cpp
index 7daea0f392..7df9c317f6 100644
--- a/cpp/models/ode_secirvvs/parameters_io.cpp
+++ b/cpp/models/ode_secirvvs/parameters_io.cpp
@@ -269,45 +269,6 @@ IOResult<void> read_confirmed_cases_data_fix_recovered(const std::vector<Confirm
     return success();
 }
 
-IOResult<std::vector<std::vector<double>>> read_population_data(const std::string& path,
-                                                                const std::vector<int>& vregion)
-{
-    BOOST_OUTCOME_TRY(auto&& population_data, mio::read_population_data(path));
-    return read_population_data(population_data, vregion);
-}
-
-IOResult<std::vector<std::vector<double>>> read_population_data(const std::vector<PopulationDataEntry>& population_data,
-                                                                const std::vector<int>& vregion)
-{
-    std::vector<std::vector<double>> vnum_population(
-        vregion.size(), std::vector<double>(ConfirmedCasesDataEntry::age_group_names.size(), 0.0));
-
-    for (auto&& county_entry : population_data) {
-        //accumulate population of states or country from population of counties
-        if (!county_entry.county_id && !county_entry.district_id) {
-            return failure(StatusCode::InvalidFileFormat, "File with county population expected.");
-        }
-        //find region that this county belongs to
-        //all counties belong to the country (id = 0)
-        auto it = std::find_if(vregion.begin(), vregion.end(), [&county_entry](auto r) {
-            return r == 0 ||
-                   (county_entry.county_id &&
-                    regions::StateId(r) == regions::get_state_id(int(*county_entry.county_id))) ||
-                   (county_entry.county_id && regions::CountyId(r) == *county_entry.county_id) ||
-                   (county_entry.district_id && regions::DistrictId(r) == *county_entry.district_id);
-        });
-        if (it != vregion.end()) {
-            auto region_idx      = size_t(it - vregion.begin());
-            auto& num_population = vnum_population[region_idx];
-            for (size_t age = 0; age < num_population.size(); age++) {
-                num_population[age] += county_entry.population[AgeGroup(age)];
-            }
-        }
-    }
-
-    return success(vnum_population);
-}
-
 } // namespace details
 } // namespace osecirvvs
 } // namespace mio
diff --git a/cpp/models/ode_secirvvs/parameters_io.h b/cpp/models/ode_secirvvs/parameters_io.h
index f6119fccf1..07456a70e2 100644
--- a/cpp/models/ode_secirvvs/parameters_io.h
+++ b/cpp/models/ode_secirvvs/parameters_io.h
@@ -425,19 +425,6 @@ IOResult<void> set_divi_data(std::vector<Model>& model, const std::string& path,
     return success();
 }
 
-/**
-        * @brief reads population data from census data.
-        * @param[in] path Path to population data file.
-        * @param[in] vregion vector of keys of the regions of interest
-        * @see mio::read_population_data
-        * @{
-        */
-IOResult<std::vector<std::vector<double>>> read_population_data(const std::string& path,
-                                                                const std::vector<int>& vregion);
-IOResult<std::vector<std::vector<double>>> read_population_data(const std::vector<PopulationDataEntry>& population_data,
-                                                                const std::vector<int>& vregion);
-/**@}*/
-
 /**
 * @brief sets population data from census data which has been read into num_population
 * @param[in, out] model vector of objects in which the data is set
@@ -641,7 +628,7 @@ template <class Model>
 IOResult<void> set_population_data(std::vector<Model>& model, const std::string& path, const std::string& path_rki,
                                    const std::vector<int>& vregion, Date date)
 {
-    BOOST_OUTCOME_TRY(auto&& num_population, details::read_population_data(path, vregion));
+    BOOST_OUTCOME_TRY(auto&& num_population, read_population_data(path, vregion));
     BOOST_OUTCOME_TRY(auto&& rki_data, mio::read_confirmed_cases_data(path_rki));
 
     BOOST_OUTCOME_TRY(set_population_data(model, num_population, rki_data, vregion, date));
@@ -841,7 +828,7 @@ IOResult<void> export_input_data_county_timeseries(
         models.size(), TimeSeries<double>::zero(num_days + 1, (size_t)InfectionState::Count * num_groups));
 
     BOOST_OUTCOME_TRY(auto&& case_data, read_confirmed_cases_data(confirmed_cases_path));
-    BOOST_OUTCOME_TRY(auto&& population_data, details::read_population_data(population_data_path, counties));
+    BOOST_OUTCOME_TRY(auto&& population_data, read_population_data(population_data_path, counties));
 
     // empty vector if set_vaccination_data is not set
     std::vector<VaccinationDataEntry> vacc_data;
diff --git a/cpp/tests/test_odesecir.cpp b/cpp/tests/test_odesecir.cpp
index b1dce952d9..8c1dc11351 100644
--- a/cpp/tests/test_odesecir.cpp
+++ b/cpp/tests/test_odesecir.cpp
@@ -26,6 +26,7 @@
 #include "ode_secir/parameter_space.h"
 #include "ode_secir/parameters.h"
 #include "ode_secir/parameters_io.h"
+#include "memilio/io/parameters_io.h"
 #include "memilio/data/analyze_result.h"
 #include "memilio/math/adapt_rk.h"
 
@@ -1216,21 +1217,6 @@ TEST(TestOdeSecir, apply_constraints_parameters)
 }
 
 #if defined(MEMILIO_HAS_JSONCPP)
-
-TEST(TestOdeSecir, read_population_data_one_age_group)
-{
-    std::string path = mio::path_join(TEST_DATA_DIR, "county_current_population.json");
-    const std::vector<int> region{1001};
-    auto result_one_age_group       = mio::osecir::details::read_population_data(path, region, true).value();
-    auto result_multiple_age_groups = mio::osecir::details::read_population_data(path, region, false).value();
-    EXPECT_EQ(result_one_age_group.size(), 1);
-    EXPECT_EQ(result_one_age_group[0].size(), 1);
-    EXPECT_EQ(result_one_age_group[0][0], 90163.0);
-
-    EXPECT_EQ(result_multiple_age_groups.size(), 1);
-    EXPECT_EQ(result_multiple_age_groups[0].size(), 6);
-    EXPECT_EQ(result_multiple_age_groups[0][0], 3433.0);
-}
 #if defined(MEMILIO_HAS_HDF5)
 
 class ModelTestOdeSecir : public testing::Test
@@ -1362,7 +1348,7 @@ TEST_F(ModelTestOdeSecir, export_time_series_init_old_date)
     // read population data
     std::string path = mio::path_join(TEST_DATA_DIR, "county_current_population.json");
     const std::vector<int> region{1002};
-    auto population_data = mio::osecir::details::read_population_data(path, region, false).value();
+    auto population_data = mio::read_population_data(path, region).value();
 
     // So, the expected values are the population data in the susceptible compartments and zeros in the other compartments.
     for (size_t i = 0; i < num_age_groups; i++) {
@@ -1414,7 +1400,7 @@ TEST_F(ModelTestOdeSecir, model_initialization_old_date)
     // read population data
     std::string path = mio::path_join(TEST_DATA_DIR, "county_current_population.json");
     const std::vector<int> region{1002};
-    auto population_data = mio::osecir::details::read_population_data(path, region, false).value();
+    auto population_data = mio::read_population_data(path, region).value();
 
     // So, the expected values are the population data in the susceptible compartments and zeros in the other compartments.
     auto expected_values =
diff --git a/cpp/tests/test_odesecirvvs.cpp b/cpp/tests/test_odesecirvvs.cpp
index 695dfd2eef..43701a974d 100644
--- a/cpp/tests/test_odesecirvvs.cpp
+++ b/cpp/tests/test_odesecirvvs.cpp
@@ -28,6 +28,7 @@
 #include "memilio/epidemiology/simulation_day.h"
 #include "memilio/io/io.h"
 #include "memilio/io/result_io.h"
+#include "memilio/io/parameters_io.h"
 #include "memilio/mobility/graph.h"
 #include "memilio/utils/stl_util.h"
 #include "memilio/epidemiology/age_group.h"
@@ -792,7 +793,7 @@ TEST(TestOdeSECIRVVS, export_time_series_init_old_date)
     // read population data
     std::string path = mio::path_join(TEST_DATA_DIR, "county_current_population.json");
     const std::vector<int> region{0};
-    auto population_data = mio::osecirvvs::details::read_population_data(path, region).value();
+    auto population_data = mio::read_population_data(path, region).value();
 
     // So, the expected values are the population data in the susceptible compartments and zeros in the other compartments.
     for (auto i = 0; i < num_age_groups; i++) {
@@ -863,7 +864,7 @@ TEST(TestOdeSECIRVVS, model_initialization_old_date)
     // read population data
     std::string path = mio::path_join(TEST_DATA_DIR, "county_current_population.json");
     const std::vector<int> region{0};
-    auto population_data = mio::osecirvvs::details::read_population_data(path, region).value();
+    auto population_data = mio::read_population_data(path, region).value();
 
     // So, the expected values are the population data in the susceptible compartments and zeros in the other compartments.
     for (auto i = 0; i < num_age_groups; i++) {
@@ -900,7 +901,7 @@ TEST(TestOdeSECIRVVS, model_initialization_old_date_county)
     // read population data
     std::string path = mio::path_join(TEST_DATA_DIR, "county_current_population.json");
     const std::vector<int> region{0};
-    auto population_data = mio::osecirvvs::details::read_population_data(path, region).value();
+    auto population_data = mio::read_population_data(path, region).value();
 
     // So, the expected values are the population data in the susceptible compartments and zeros in the other compartments.
     for (auto i = 0; i < num_age_groups; i++) {
@@ -933,7 +934,7 @@ TEST(TestOdeSECIRVVS, set_population_data_overflow_vacc)
 
     std::string path_pop_data = mio::path_join(TEST_DATA_DIR, "county_current_population.json");
     const std::vector<int> region{0};
-    auto population_data = mio::osecirvvs::details::read_population_data(path_pop_data, region).value();
+    auto population_data = mio::read_population_data(path_pop_data, region).value();
 
     // we choose the date so that no case data is available
     ASSERT_THAT(mio::osecirvvs::details::set_population_data(
@@ -973,7 +974,7 @@ TEST(TestOdeSECIRVVS, set_population_data_no_data_avail)
 
     std::string path_pop_data = mio::path_join(TEST_DATA_DIR, "county_current_population.json");
     const std::vector<int> region{0};
-    auto population_data = mio::osecirvvs::details::read_population_data(path_pop_data, region).value();
+    auto population_data = mio::read_population_data(path_pop_data, region).value();
 
     // we choose the date so that no case data is available
     ASSERT_THAT(mio::osecirvvs::details::set_population_data(

From 6aba288d633e3c7072635850a30c362f79687da9 Mon Sep 17 00:00:00 2001
From: HenrZu <69154294+HenrZu@users.noreply.github.com>
Date: Fri, 21 Mar 2025 11:13:19 +0100
Subject: [PATCH 3/7] [ci skip] doc: 2024 -> 2025

---
 cpp/memilio/io/parameters_io.cpp | 2 +-
 cpp/memilio/io/parameters_io.h   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/cpp/memilio/io/parameters_io.cpp b/cpp/memilio/io/parameters_io.cpp
index a547e1508b..f9f9f8b3c0 100644
--- a/cpp/memilio/io/parameters_io.cpp
+++ b/cpp/memilio/io/parameters_io.cpp
@@ -1,5 +1,5 @@
 /* 
-* Copyright (C) 2020-2024 MEmilio
+* Copyright (C) 2020-2025 MEmilio
 *
 * Authors: Henrik Zunker
 *
diff --git a/cpp/memilio/io/parameters_io.h b/cpp/memilio/io/parameters_io.h
index 9aedfe6072..14b333e3aa 100644
--- a/cpp/memilio/io/parameters_io.h
+++ b/cpp/memilio/io/parameters_io.h
@@ -1,5 +1,5 @@
 /* 
-* Copyright (C) 2020-2024 MEmilio
+* Copyright (C) 2020-2025 MEmilio
 *
 * Authors: Henrik Zunker
 *

From 3e7c55cd1d2139ef5919bf698f353afe4a098e8d Mon Sep 17 00:00:00 2001
From: HenrZu <69154294+HenrZu@users.noreply.github.com>
Date: Fri, 30 May 2025 11:28:57 +0200
Subject: [PATCH 4/7] add tests for cov

---
 cpp/tests/test_odesecir.cpp | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/cpp/tests/test_odesecir.cpp b/cpp/tests/test_odesecir.cpp
index 944e74a75c..0fc35ec7c2 100644
--- a/cpp/tests/test_odesecir.cpp
+++ b/cpp/tests/test_odesecir.cpp
@@ -1447,6 +1447,22 @@ TEST(TestOdeSecir, set_divi_data_invalid_dates)
     mio::set_log_level(mio::LogLevel::warn);
 }
 
+TEST(TestOdeSecir, set_divi_data_empty_data)
+{
+    // Create an empty DIVI data vector
+    std::vector<mio::DiviEntry> empty_data;
+    std::vector<int> regions = {0, 1};
+    std::vector<double> num_icu(regions.size(), 0.0);
+    mio::Date date(2020, 4, 1);
+
+    auto result = mio::compute_divi_data(empty_data, regions, date, num_icu);
+
+    // Expect failure due to empty DIVI data
+    EXPECT_FALSE(result);
+    EXPECT_EQ(result.error().code(), mio::StatusCode::InvalidValue);
+    EXPECT_EQ(result.error().message(), "DIVI data is empty.");
+}
+
 TEST_F(ModelTestOdeSecir, set_confirmed_cases_data_with_ICU)
 {
     // set params
@@ -1492,5 +1508,19 @@ TEST_F(ModelTestOdeSecir, set_confirmed_cases_data_with_ICU)
     }
 }
 
+TEST(TestOdeSecir, read_population_data_failure)
+{
+    // Create invalid population data entry without county_id or district_id
+    std::vector<mio::PopulationDataEntry> invalid_data;
+    mio::PopulationDataEntry invalid_entry;
+    invalid_data.push_back(invalid_entry);
+
+    // Test that read_population_data returns failure with correct message
+    auto result = mio::read_population_data(invalid_data, {1001});
+    EXPECT_FALSE(result);
+    EXPECT_EQ(result.error().code(), mio::StatusCode::InvalidFileFormat);
+    EXPECT_EQ(result.error().message(), "File with county population expected.");
+}
+
 #endif
 #endif

From 0f0d49867c6605956689c61c49f219e6fe1e4ab5 Mon Sep 17 00:00:00 2001
From: Henrik Zunker <69154294+HenrZu@users.noreply.github.com>
Date: Tue, 17 Jun 2025 09:17:05 +0200
Subject: [PATCH 5/7] Apply suggestions from code review

Co-authored-by: jubicker <113909589+jubicker@users.noreply.github.com>
---
 cpp/memilio/io/parameters_io.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/cpp/memilio/io/parameters_io.h b/cpp/memilio/io/parameters_io.h
index 14b333e3aa..50581afef4 100644
--- a/cpp/memilio/io/parameters_io.h
+++ b/cpp/memilio/io/parameters_io.h
@@ -58,7 +58,7 @@ int get_region_id(const EpiDataEntry& data_entry)
  * @param[in] divi_data Vector of DIVI data entries containing date, region, and ICU information.
  * @param[in] vregion Vector of region IDs for which the data is computed.
  * @param[in] date Date for which the ICU data is computed.
- * @param[out] vnum_icu Output vector containing the number of ICU cases for each region.
+ * @param[in, out] vnum_icu Output vector containing the number of ICU cases for each region.
  *
  * @return An IOResult indicating success or failure.
  */
@@ -101,7 +101,7 @@ IOResult<void> compute_divi_data(const std::vector<DiviEntry>& divi_data, const
  * @param[in] path Path to the file containing DIVI data.
  * @param[in] vregion Vector of region IDs for which the data is computed.
  * @param[in] date Date for which the ICU data is computed.
- * @param[out] vnum_icu Output vector containing the number of ICU cases for each region.
+ * @param[in, out] vnum_icu Output vector containing the number of ICU cases for each region.
  *
  * @return An IOResult indicating success or failure.
  */

From f8f729f5a6a78bd764ac8cffcdc413312a92c3c3 Mon Sep 17 00:00:00 2001
From: HenrZu <69154294+HenrZu@users.noreply.github.com>
Date: Tue, 17 Jun 2025 09:25:25 +0200
Subject: [PATCH 6/7] [ci skip] rm space in doc, add param names

---
 cpp/memilio/io/parameters_io.h | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/cpp/memilio/io/parameters_io.h b/cpp/memilio/io/parameters_io.h
index 50581afef4..2fe7cc3224 100644
--- a/cpp/memilio/io/parameters_io.h
+++ b/cpp/memilio/io/parameters_io.h
@@ -33,7 +33,8 @@
 namespace mio
 {
 /**
- * @brief Gets the region ID (county, state, or district) of an EpiDataEntry.
+ * @brief Gets the region ID (county, state, or district) of an EpiDataEntry. If none are available, 
+ * it defaults to 0 which is representing the whole country.
  * 
  * If none are available, it defaults to 0 which is representing the whole country.
  * 
@@ -121,8 +122,8 @@ IOResult<void> read_divi_data(const std::string& path, const std::vector<int>& v
  * @return An IOResult containing a vector of vectors, where each inner vector represents the population
  *         distribution across age groups for a specific region, or an error if the function fails.
  */
-IOResult<std::vector<std::vector<double>>> read_population_data(const std::vector<PopulationDataEntry>&,
-                                                                const std::vector<int>&);
+IOResult<std::vector<std::vector<double>>> read_population_data(const std::vector<PopulationDataEntry>& population_data,
+                                                                const std::vector<int>&) vregion;
 
 /**
  * @brief Reads population data from census data.
@@ -132,7 +133,8 @@ IOResult<std::vector<std::vector<double>>> read_population_data(const std::vecto
  * @return An IOResult containing a vector of vectors, where each inner vector represents the population
  *         distribution across age groups for a specific region, or an error if the function fails.
  */
-IOResult<std::vector<std::vector<double>>> read_population_data(const std::string&, const std::vector<int>&);
+IOResult<std::vector<std::vector<double>>> read_population_data(const std::string& path,
+                                                                const std::vector<int>& vregion);
 
 } // namespace mio
 

From fd8fb0ed2936e46daf911a25aea680deabbb6d3d Mon Sep 17 00:00:00 2001
From: HenrZu <69154294+HenrZu@users.noreply.github.com>
Date: Tue, 17 Jun 2025 09:53:10 +0200
Subject: [PATCH 7/7] typo

---
 cpp/memilio/io/parameters_io.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cpp/memilio/io/parameters_io.h b/cpp/memilio/io/parameters_io.h
index 2fe7cc3224..3ea00fc73b 100644
--- a/cpp/memilio/io/parameters_io.h
+++ b/cpp/memilio/io/parameters_io.h
@@ -123,7 +123,7 @@ IOResult<void> read_divi_data(const std::string& path, const std::vector<int>& v
  *         distribution across age groups for a specific region, or an error if the function fails.
  */
 IOResult<std::vector<std::vector<double>>> read_population_data(const std::vector<PopulationDataEntry>& population_data,
-                                                                const std::vector<int>&) vregion;
+                                                                const std::vector<int>& vregion);
 
 /**
  * @brief Reads population data from census data.