diff --git a/classes/sph0/louis/src_cpp/FixedParticle.h b/classes/sph0/louis/src_cpp/FixedParticle.h
index 2ce559dc..6ab0e2f1 100644
--- a/classes/sph0/louis/src_cpp/FixedParticle.h
+++ b/classes/sph0/louis/src_cpp/FixedParticle.h
@@ -8,7 +8,7 @@ class FixedParticle : public Particle
 
 {
 public:
-    FixedParticle(Model &m);
+    explicit FixedParticle(Model &m);
 
     virtual void update_vars() override;
 };
diff --git a/classes/sph0/louis/src_cpp/MobileParticle.h b/classes/sph0/louis/src_cpp/MobileParticle.h
index 6e4b801c..41a9a696 100644
--- a/classes/sph0/louis/src_cpp/MobileParticle.h
+++ b/classes/sph0/louis/src_cpp/MobileParticle.h
@@ -11,7 +11,7 @@
 class MobileParticle : public FixedParticle
 {
 public:
-    MobileParticle(Model &m);
+    explicit MobileParticle(Model &m);
 
     virtual void update_vars() override;
 
diff --git a/classes/sph0/louis/src_cpp/Model.cpp b/classes/sph0/louis/src_cpp/Model.cpp
index 9adf27ef..dfb94b3e 100644
--- a/classes/sph0/louis/src_cpp/Model.cpp
+++ b/classes/sph0/louis/src_cpp/Model.cpp
@@ -18,6 +18,19 @@ Model::Model()
     this->timeStep = 1.0e-15;
     this->currentTime = 0.0;
     this->RKstep = 0;
+
+    // init other variables
+    this->numFP = 0;
+    this->numMP = 0;
+    this->h_0 = 0.0;
+    this->dom_dim = 0.0;
+    this->alpha = 0.0;
+    this->beta = 0.0;
+    this->kappa = 0.0;
+    this->kernelCorrection = 0.0;
+    this->maxTime = 0.0;
+    this->saveInt = 0.0;
+    this->numPart = 0;
 }
 
 Model::~Model()
@@ -264,7 +277,7 @@ Model::update_dt()
     double dTf = std::numeric_limits<double>::max();
     for (int i = this->numFP + 1; i < this->numPart; i++)
     {
-        Particle *p = this->particles[i];
+        Particle const *p = this->particles[i];
         double dt = sqrt(p->h / 9.81);
         if (dt < dTf)
             dTf = dt;
diff --git a/classes/sph0/louis/src_cpp/Particle.cpp b/classes/sph0/louis/src_cpp/Particle.cpp
index 9658f165..cfbf6ab2 100644
--- a/classes/sph0/louis/src_cpp/Particle.cpp
+++ b/classes/sph0/louis/src_cpp/Particle.cpp
@@ -47,7 +47,7 @@ void
 Particle::getNeighbours()
 {
     int RKstep = this->model.RKstep;
-    Eigen::Vector3d &xyz = this->coord[RKstep]; // position of the particle
+    Eigen::Vector3d const &xyz = this->coord[RKstep]; // position of the particle
 
     if (RKstep == 0)
     {
@@ -115,7 +115,7 @@ Particle::getNeighbours()
                 for (size_t j = 0; j < cells->size(); j++)
                 {
                     Particle *p = (*cells)[j];
-                    Eigen::Vector3d &neighXYZ = p->coord[RKstep];
+                    Eigen::Vector3d const &neighXYZ = p->coord[RKstep];
                     double r = (xyz - neighXYZ).norm();
                     if (r <= this->model.kappa * this->h)
                     {
@@ -149,7 +149,7 @@ Particle::getNeighbours()
         for (size_t i = 0; i < this->neighbours.size(); i++)
         {
             Neighbour *neigh = &this->neighbours[i];
-            Eigen::Vector3d &neighXYZ = neigh->p->coord[RKstep];
+            Eigen::Vector3d const &neighXYZ = neigh->p->coord[RKstep];
             neigh->r = (xyz - neighXYZ).norm();
         }
     }
@@ -167,7 +167,7 @@ Particle::gradW()
     if (this->neighbours.size() > 150)
         throw std::runtime_error("number of neighbours greater than expected (max 150 for vec_gradW): " + std::to_string(this->neighbours.size()));
 
-    double h = this->h;
+    // double h = this->h;
     int RKstep = this->model.RKstep;
 
     for (size_t i = 0; i < this->neighbours.size(); i++)
@@ -198,8 +198,8 @@ Particle::kernel_corr()
     for (size_t i = 0; i < this->neighbours.size(); i++)
     {
         Particle *neigh = this->neighbours[i].p;
-        Eigen::Vector3d &pb = neigh->coord[RKstep];
-        Eigen::Vector3d &pa = this->coord[RKstep];
+        Eigen::Vector3d const &pb = neigh->coord[RKstep];
+        Eigen::Vector3d const &pa = this->coord[RKstep];
 
         double factor = neigh->m / neigh->rho[RKstep];
         M += factor * (pb - pa) * this->vec_gradW[i].transpose();
diff --git a/classes/sph0/louis/src_cpp/QtVTKHook.h b/classes/sph0/louis/src_cpp/QtVTKHook.h
index 0c0e568a..a030dc8c 100644
--- a/classes/sph0/louis/src_cpp/QtVTKHook.h
+++ b/classes/sph0/louis/src_cpp/QtVTKHook.h
@@ -26,7 +26,8 @@ class DisplayWindow : public QWidget
 public:
     DisplayWindow(Model &model, QWidget *parent = nullptr);
     ~DisplayWindow();
-void updateParticlePositions();
+    
+    void updateParticlePositions();
 
 private:
     void setupGUI();
diff --git a/classes/sph0/louis/src_cpp/Sorter.cpp b/classes/sph0/louis/src_cpp/Sorter.cpp
index 25aba841..b24b8435 100644
--- a/classes/sph0/louis/src_cpp/Sorter.cpp
+++ b/classes/sph0/louis/src_cpp/Sorter.cpp
@@ -8,6 +8,8 @@
 
 Sorter::Sorter(Model &m) : model(m)
 {
+    this->dx = 0.0;
+    this->nx = 0;
 }
 
 /// Put every particle in their corresponding cell.
@@ -23,9 +25,9 @@ Sorter::execute()
     for(auto &cell : this->cells)
         cell.clear();
 
-    for(auto &p : this->model.particles)
+    for(auto const &p : this->model.particles)
     {
-        Eigen::Vector3d &pos = p->coord[this->model.RKstep];
+        Eigen::Vector3d const &pos = p->coord[this->model.RKstep];
 
         int ix = (int)((pos(0) - fmod(pos(0), this->dx)) / this->dx) + 1;
         int iy = (int)((pos(1) - fmod(pos(1), this->dx)) / this->dx) + 1;
diff --git a/classes/sph0/louis/src_cpp/Sorter.h b/classes/sph0/louis/src_cpp/Sorter.h
index a843bbcc..81660afe 100644
--- a/classes/sph0/louis/src_cpp/Sorter.h
+++ b/classes/sph0/louis/src_cpp/Sorter.h
@@ -19,7 +19,7 @@ class Sorter
     std::vector<std::vector<Particle *>> cells; 
 
 public:
-    Sorter(Model &m);
+    explicit Sorter(Model &m);
 
     void execute();