fixed bug with automated selection of gamma for tensor-based and staggered grid method

include/ALL_Staggered.hpp

@@ -266,7 +266,7 @@ template <class T, class W> void Staggered_LB<T, W>::balance(int) {
     // automatic selection of gamma to guarantee stability of method (choice of
     // user gamma ignored)
     this->gamma =
-        std::max(4.1, 1.1 * (1.0 + std::max(local_size, remote_size) /
+        std::max(4.1, 2.0 * (1.0 + std::max(local_size, remote_size) /
                                        std::min(local_size, remote_size)));
 
 #ifdef ALL_DEBUG_ENABLED

include/ALL_Tensor.hpp

@@ -216,6 +216,12 @@ template <class T, class W> void Tensor_LB<T, W>::balance(int) {
     MPI_Wait(&sreq, &sstat);
     MPI_Wait(&rreq, &rstat);
 
+    // automatic selection of gamma to guarantee stability of method (choice of
+    // user gamma ignored)
+    this->gamma =
+        std::max(4.1, 2.0 * (1.0 + std::max(local_size, remote_size) /
+                                       std::min(local_size, remote_size)));
+
     T shift = Functions::borderShift1d(
         rank_right, this->local_coords.at(i), this->global_dims.at(i),
         work_local_plane, remote_work, local_size, remote_size, this->gamma,