added time variable to seed calculation

cpp/full_code/ornstein_uhlenbeck_process.cpp

@@ -4,7 +4,7 @@
 #include <cassert>
 #include "scope_timer.hpp"
 #include <algorithm>
-
+#include <chrono>
 
 
 template <class rnumber,field_backend be>
@@ -28,7 +28,7 @@ ornstein_uhlenbeck_process<rnumber,be>::ornstein_uhlenbeck_process(
     this->ou_field = new field<rnumber,be,THREE>(
         nx,ny,nz, MPI_COMM_WORLD, FFTW_PLAN_RIGOR);
     *this->ou_field = 0.0;
-    this->ou_field->dft(); 
+    this->ou_field->dft();
 
     this->ou_field_vort = new field<rnumber,be,THREE>(
         nx,ny,nz, MPI_COMM_WORLD, FFTW_PLAN_RIGOR);
@@ -46,19 +46,26 @@ ornstein_uhlenbeck_process<rnumber,be>::ornstein_uhlenbeck_process(
     this->ou_energy_amplitude = ou_energy_amplitude;
     this->epsilon = pow((this->ou_energy_amplitude/this->kolmogorov_constant), 3./2.);
 
-    assert(this->kk->kM2 >= this->ou_kmax_squ); 
+    assert(this->kk->kM2 >= this->ou_kmax_squ);
 
     gen.resize(omp_get_max_threads());
 
+    long now;
+
+    if (this->ou_field->clayout->myrank == 0){
+	now = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
+    }
+    MPI_Bcast(&now,1,MPI_LONG,0,this->ou_field->comm);
+
     for(int thread=0;thread<omp_get_max_threads();thread++)
     {
-            int current_seed = 
+            long current_seed =
                     this->ou_field->clayout->myrank*omp_get_max_threads() +
-                    thread;
+                    thread+now;
             gen[thread].seed(current_seed);
     }
 
-    
+
     this->initialize_B();
 
 }