diff --git a/Correction/Makefile b/Correction/Makefile
new file mode 100644
index 0000000000000000000000000000000000000000..c6e329fd2d0139683c0bc54eac1dc87ae16ad17c
--- /dev/null
+++ b/Correction/Makefile
@@ -0,0 +1,15 @@
+.PHONY:clean all
+
+CC=nvc++
+FLAGS=-std=c++20 -stdpar=gpu -O3 -g
+
+all: artefacts/heat_gpu
+
+artefacts/%: artefacts/%.o
+ $(CC) $(FLAGS) $^ -o $@
+
+artefacts/%.o: %.cpp
+ $(CC) $(FLAGS) -c $^ -o $@
+
+clean:
+ rm -vf artefacts/**
\ No newline at end of file
diff --git a/Correction/artefacts/.gitkeep b/Correction/artefacts/.gitkeep
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git a/Correction/figure.py b/Correction/figure.py
new file mode 100644
index 0000000000000000000000000000000000000000..06cd53409e516f7f89c771e05afa36511e01128c
--- /dev/null
+++ b/Correction/figure.py
@@ -0,0 +1,20 @@
+import pandas as pd
+import matplotlib.pyplot as plt
+import sys
+
+if len(sys.argv) < 3:
+ print("Usage: python script.py input_csv_file output_pdf_file")
+ sys.exit(1)
+
+file_path = sys.argv[1]
+output_file_path = sys.argv[2]
+
+data = pd.read_csv(file_path, header=None)
+
+plt.figure(figsize=(10, 8))
+plt.imshow(data, cmap='hot', interpolation='nearest')
+plt.colorbar()
+
+plt.savefig(output_file_path, bbox_inches='tight')
+
+plt.close()
\ No newline at end of file
diff --git a/Correction/heat_gpu.cpp b/Correction/heat_gpu.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..ea2d248af1194da7d22639149c359e1e30619e14
--- /dev/null
+++ b/Correction/heat_gpu.cpp
@@ -0,0 +1,104 @@
+#include <algorithm>
+#include <chrono>
+#include <execution>
+#include <iostream>
+#include <ranges>
+#include <string>
+
+#include "matrix.h"
+
+constexpr auto kPolicy = std::execution::par_unseq;
+
+template <typename T>
+void stepSlow(Matrix<T> ¤t, Matrix<T> &next) {
+ auto cols = current.cols();
+
+ auto idxs_rows = std::views::iota(1, rows - 1);
+ std::for_each(kPolicy,
+ idxs_rows.begin(), idxs_rows.end(),
+ [cur = current.dataSpan(),
+ nxt = next.dataSpan(),
+ cols](int i) {
+ auto idxs_cols = std::views::iota(1, cols - 1);
+ std::for_each(
+ idxs_cols.begin(), idxs_cols.end(),
+ [cur, nxt, cols, row = i * cols](int j) {
+ auto idx = row + j; // we need a 1d index for the spans
+ nxt[idx] = 0.25 * (cur[idx - 1] +
+ cur[idx + 1] +
+ cur[idx - cols] +
+ cur[idx + cols]);
+ });
+ });
+}
+
+template <typename T>
+void step(Matrix<T> ¤t, Matrix<T> &next) {
+ auto cols = current.cols();
+ auto rows = current.rows();
+
+ auto up = -1 * cols;
+ auto down = cols;
+ auto left = -1;
+ auto right = 1;
+
+ auto idxs = std::views::iota(0, (cols - 2) * (rows - 2));
+
+ std::for_each(kPolicy,
+ idxs.begin(), idxs.end(),
+ [cur = current.dataSpan(),
+ nxt = next.dataSpan(),
+ cols,
+ up, down, left, right](int idx) {
+ // We compute the 1d index to access the spans
+ auto r = idx / (cols - 2);
+ auto c = idx % (cols - 2);
+ auto i = (r + 1) * cols + c + 1;
+ nxt[i] = 0.25 * (cur[i + left] +
+ cur[i + right] +
+ cur[i + up] +
+ cur[i + down]);
+ });
+}
+
+int main(int argc, char **argv) {
+ int m = std::stoi(argv[1]);
+ int n = std::stoi(argv[2]);
+ int tmax = std::stoi(argv[3]);
+ std::string filename = argv[4];
+
+ auto start_global = std::chrono::steady_clock::now();
+
+ std::cout << "processors : seq" << std::endl;
+ std::cout << "m : " << m << std::endl;
+ std::cout << "n : " << n << std::endl;
+ std::cout << "tmax : " << tmax << std::endl;
+
+ Matrix<double> *U = new Matrix<double>(m, n);
+ Matrix<double> *Unext = new Matrix<double>(m, n);
+ init_matrix(*U);
+ init_matrix(*Unext);
+
+ auto start_iter = std::chrono::steady_clock::now();
+ for (int t = 0; t < tmax; t++) {
+ step(*U, *Unext);
+ std::swap(U, Unext);
+ if (t % 100 == 0) {
+ std::cout << "t:" << t << std::endl;
+ }
+ }
+ auto end_iter = std::chrono::steady_clock::now();
+ auto duration_iter = std::chrono::duration<double>(end_iter - start_iter);
+
+ std::cout << "iterations time : " << duration_iter.count() << "[s]" << std::endl;
+
+ write_mat(*U, filename);
+ std::cout << "sum of elements of matrix : " << sum_mat(*U) << std::endl;
+
+ delete U;
+ delete Unext;
+
+ auto end_global = std::chrono::steady_clock::now();
+ auto duration_global = std::chrono::duration<double>(end_global - start_global);
+ std::cout << "total time : " << duration_global.count() << "[s]" << std::endl;
+}
\ No newline at end of file
diff --git a/Correction/matrix.h b/Correction/matrix.h
new file mode 100644
index 0000000000000000000000000000000000000000..46fbc1c1b6d1a067970b9b898758423fcb6a8a9c
--- /dev/null
+++ b/Correction/matrix.h
@@ -0,0 +1,112 @@
+#include <fstream>
+#include <span>
+#include <stdexcept>
+
+// a simple generic Matrix class
+// templates in c++ allows genericity
+// https://en.cppreference.com/w/cpp/language/templates
+template <typename T>
+class Matrix {
+ public:
+ // constructor, allocate linear array and
+ // arrange pointer for 2D array
+ Matrix<T>(int m, int n) {
+ this->m = m;
+ this->n = n;
+ mat = new T *[m];
+ mat[0] = new T[m * n];
+ for (int i = 0; i < m; i++) {
+ mat[i] = &(mat[0][i * n]);
+ }
+ }
+ // accessor [] of class Matrix returns a pointer
+ // to the corresponding line
+ T *operator[](int index) {
+ if (index < 0 || index >= m) {
+ throw std::out_of_range("Index out of range");
+ }
+ return mat[index];
+ }
+ // destructor of class Matrix
+ // automatically called when object goes out of scope
+ ~Matrix() {
+ delete[] mat[0];
+ delete[] mat;
+ }
+ int cols() {
+ return n;
+ }
+ int rows() {
+ return m;
+ }
+
+ std::span<T> dataSpan() {
+ return std::span<T>(this->mat[0], n * m);
+ }
+
+ private:
+ int m, n;
+ T **mat;
+};
+
+// initialise a Matrix
+// here, & is the symbol for reference
+// which allows passing an object by reference
+// without using pointer syntax
+// https://en.cppreference.com/w/cpp/language/reference
+template <typename T>
+void init_matrix(Matrix<T> &mat) {
+ for (int i = 0; i < mat.rows(); i++) {
+ for (int j = 0; j < mat.cols(); j++) {
+ mat[i][j] = 0;
+ }
+ }
+ for (int i = 0; i < mat.rows(); i++) {
+ mat[i][0] = 0;
+ mat[i][mat.cols() - 1] = 1;
+ }
+ for (int j = 0; j < mat.cols(); j++) {
+ mat[0][j] = 1;
+ mat[mat.rows() - 1][j] = 0;
+ }
+}
+
+template <typename T>
+void print_mat(Matrix<T> &m) {
+ for (int i = 0; i < m.rows(); i++) {
+ for (int j = 0; j < m.cols(); j++) {
+ std::cout << m[i][j] << ", ";
+ }
+ std::cout << std::endl;
+ }
+}
+
+template <typename T>
+void write_mat(Matrix<T> &m, std::string filename) {
+ std::ofstream file(filename);
+ if (!file.is_open()) {
+ std::cerr << "Failed to open file for writing: " << filename << std::endl;
+ return;
+ }
+ for (int i = 0; i < m.rows(); i++) {
+ for (int j = 0; j < m.cols(); j++) {
+ file << m[i][j];
+ if (j != m.cols() - 1) {
+ file << ",";
+ }
+ }
+ file << std::endl;
+ }
+ file.close();
+}
+
+template <typename T>
+T sum_mat(Matrix<T> &m) {
+ T sum = 0;
+ for (int i = 0; i < m.rows(); i++) {
+ for (int j = 0; j < m.cols(); j++) {
+ sum += m[i][j];
+ }
+ }
+ return sum;
+}
\ No newline at end of file
diff --git a/Correction/run_baobab.sh b/Correction/run_baobab.sh
new file mode 100644
index 0000000000000000000000000000000000000000..3dd28fba7bc1c8677b1f877e342d1589f5ad8101
--- /dev/null
+++ b/Correction/run_baobab.sh
@@ -0,0 +1,11 @@
+#!/bin/sh
+#SBATCH --job-name=heat_gpu
+#SBATCH --output=heat_gpu.o%j
+#SBATCH --time=00:30:00
+#SBATCH --partition=shared-gpu
+#SBATCH --gpus=1
+#SBATCH --constraint="COMPUTE_TYPE_AMPERE|COMPUTE_TYPE_TURING|"
+
+module load NVHPC/24.1-CUDA-12.3.0
+
+srun ./artefacts/heat_gpu 10000 10000 10000 output_$SLURM_JOBID.csv
\ No newline at end of file
diff --git a/Correction/run_one_job.sh b/Correction/run_one_job.sh
new file mode 100644
index 0000000000000000000000000000000000000000..c26c68898eb76ccf6aa10240cd42ff0685faa275
--- /dev/null
+++ b/Correction/run_one_job.sh
@@ -0,0 +1,16 @@
+#!/bin/sh
+#SBATCH --job-name=heat
+#SBATCH --output=heat.o%j
+#SBATCH --cpus-per-task=1
+#SBATCH --mem-per-cpu=2000
+#SBATCH --partition=shared-cpu
+#SBATCH --time=01:00:00
+#SBATCH --constraint=EPYC-7742
+
+echo $SLURM_NODELIST
+
+module purge
+module load foss/2023a
+
+srun heat_par 10000 10000 10000 output_$SLURM_JOBID.csv
+rm output_$SLURM_JOBID.csv
diff --git a/Correction/run_yggdrasil.sh b/Correction/run_yggdrasil.sh
new file mode 100644
index 0000000000000000000000000000000000000000..5fef0d22cf1d18183bac5e51232aa7bc69ae152a
--- /dev/null
+++ b/Correction/run_yggdrasil.sh
@@ -0,0 +1,11 @@
+#!/bin/sh
+#SBATCH --job-name=heat_gpu
+#SBATCH --output=heat_gpu.o%j
+#SBATCH --time=00:30:00
+#SBATCH --partition=shared-gpu
+#SBATCH --gpus=1
+#SBATCH --constraint="COMPUTE_TYPE_TURING"
+
+module load NVHPC/24.1-CUDA-12.3.0
+
+srun ./artefacts/heat_gpu 10000 10000 10000 output_$SLURM_JOBID.csv
\ No newline at end of file