fix init in set particles

fluid/fluid_problem.c

@@ -1766,6 +1766,11 @@ void fluid_problem_set_particles(FluidProblem *problem, int n, double *mass, dou
     problem->particle_contact = (double*)malloc(sizeof(double)*n*D);
   }
   for (int i = 0; i < n; ++i) {
+    for (int k = 0; k < D; ++k) {
+      problem->particle_position[i*D+k] = position[i*D+k];
+      problem->particle_velocity[i*D+k] = velocity[i*D+k];
+      problem->particle_contact[i*D+k] = contact[i*D+k];
+    }
     problem->particle_element_id[i]=-1;
   }
   mesh_tree_particle_to_mesh(problem->mesh_tree, n, position, problem->particle_element_id, problem->particle_uvw);

python/time_integration.py

@@ -91,7 +91,6 @@ def predictor_corrector_iterate(fluid, particles, dt, min_nsub=1, contact_tol=1e
     disk0 = np.copy(particles.disks())
     if particles.dim() == 3 :
         tri0 = np.copy(particles.triangles())
-
     # Predictor
     #
     # Compute the fluid solution and keep a copy of this solution and the forces applied by the fluid on the grains