Adding rudimentary computeTimeChunck functionality in particleset.execute

Author: erikvansebille

parcels/field.py

@@ -147,7 +147,7 @@ def __init__(
         _assert_compatible_combination(data, grid)
 
         self.name = name
-        self.data = data
+        self.data_full = data
         self.grid = grid
 
         try:
@@ -186,7 +186,7 @@ def __init__(
         else:
             raise ValueError("Unsupported mesh type in data array attributes. Choose either: 'spherical' or 'flat'")
 
-        if "time" not in self.data.dims:
+        if "time" not in data.dims:
             raise ValueError("Field is missing a 'time' dimension. ")
 
     @property
@@ -201,27 +201,27 @@ def units(self, value):
 
     @property
     def xdim(self):
-        if type(self.data) is xr.DataArray:
+        if type(self.data_full) is xr.DataArray:
             return self.grid.xdim
         else:
             raise NotImplementedError("xdim not implemented for unstructured grids")
 
     @property
     def ydim(self):
-        if type(self.data) is xr.DataArray:
+        if type(self.data_full) is xr.DataArray:
             return self.grid.ydim
         else:
             raise NotImplementedError("ydim not implemented for unstructured grids")
 
     @property
     def zdim(self):
-        if type(self.data) is xr.DataArray:
+        if type(self.data_full) is xr.DataArray:
             return self.grid.zdim
         else:
-            if "nz1" in self.data.dims:
-                return self.data.sizes["nz1"]
-            elif "nz" in self.data.dims:
-                return self.data.sizes["nz"]
+            if "nz1" in self.data_full.dims:
+                return self.data_full.sizes["nz1"]
+            elif "nz" in self.data_full.dims:
+                return self.data_full.sizes["nz"]
             else:
                 return 0
 

parcels/particleset.py

@@ -805,10 +805,16 @@ def execute(
 
         time = start_time
         while sign_dt * (time - end_time) < 0:
+
+            for fld in [self.fieldset.U, self.fieldset.V]:  # TODO generalise to all fields
+                ti = np.argmin(fld.data_full.time.data <= self._data["time_nextloop"][0]) - 1  # TODO also implement dt < 0
+                if not hasattr(fld, "data") or fld.data_full.time.data[ti] != fld.data.time.data[0]:
+                    fld.data = fld.data_full.isel({"time": slice(ti, ti + 2)}).load()
+
             if sign_dt > 0:
-                next_time = end_time  # TODO update to min(next_output, end_time) when ParticleFile works
+                next_time = min(time + dt, end_time)
             else:
-                next_time = end_time  # TODO update to max(next_output, end_time) when ParticleFile works
+                next_time = max(time - dt, end_time)
             res = self._kernel.execute(self, endtime=next_time, dt=dt)
             if res == StatusCode.StopAllExecution:
                 return StatusCode.StopAllExecution