adds mechanism for control of initial condition behavior

TurTLE/DNS.py

@@ -929,16 +929,32 @@ class DNS(_code):
         return None
     def generate_initial_condition(
             self,
-            opt = None):
+            opt = None,
+            need_field = None,
+            checkpoint_field = None):
+        """Creates the "checkpoint 0" file.
+
+        Keyword arguments:
+        opt              --- options object, this method may access any of
+                                * opt.src_simname,
+                                * opt.src_work_dir,
+                                * opt.src_iteration
+        need_field       --- boolean: does the DNS need the "0" iteration field
+                             to be present in the "checkpoint 0" file?
+        checkpoint_field --- string: name of field used for checkpoints, one of
+                             'velocity' or 'vorticity'.
+        """
         # take care of fields' initial condition
-        # first, check if initial field exists
-        need_field = False
-        if self.check_current_vorticity_exists:
-            need_field = True
+        if type(checkpoint_field) == type(None):
             if self.dns_type in ['NSE', 'NSE_alt_dealias']:
                 checkpoint_field = 'velocity'
             else:
                 checkpoint_field = 'vorticity'
+        # first, check if initial field exists
+        if type(need_field) == type(None):
+            need_field = False
+            if self.check_current_vorticity_exists:
+                need_field = True
             if self.dns_type in [
                     'NSE',
                     'NSE_alt_dealias',