updates NSE initiialization

cpp/full_code/NSE.cpp

@@ -56,8 +56,12 @@ int NSE<rnumber>::initialize(void)
 
     /* initialize field */
     this->velocity->real_space_representation = false;
-    if ((this->iteration == 0)
-     && (this->field_random_seed != 0)) {
+    if (this->iteration == 0) {
+        if (!hdf5_tools::field_exists(
+                    this->get_current_fname(),
+                    "velocity",
+                    "complex",
+                    0)) {
             TIMEZONE("NSE::initialize::generate_initial_condition");
             // generate initial condition
             make_gaussian_random_field(
@@ -89,6 +93,14 @@ int NSE<rnumber>::initialize(void)
                 this->iteration,
                 true);
         }
+    } else {
+        TIMEZONE("NSE::initialize::read_initial_condition");
+        this->velocity->io(
+            this->get_current_fname(),
+            "velocity",
+            this->iteration,
+            true);
+    }
     return EXIT_SUCCESS;
 }