add gpm cleanup function to add timeMidScan variable when it is not t…

…here

podaac/subsetter/gpm_cleanup.py

@@ -3,8 +3,19 @@
 to nscan, nbin, nfreq by using the DimensionNames variable attribute
 """
 
+import datetime
+from netCDF4 import date2num
+
 dim_dict = {}
 
+def create_new_time_var(time_group, nc_dataset):
+    time_unit_out = "seconds since 1980-01-06 00:00:00"
+    new_time_list = [date2num(datetime.datetime(nc_dataset[time_group+'__Year'][:][i], nc_dataset[time_group+'__Month'][:][i], nc_dataset[time_group+'__DayOfMonth'][:][i],
+                                            hour=nc_dataset[time_group+'__Hour'][:][i], minute=nc_dataset[time_group+'__Minute'][:][i],
+                                            second=nc_dataset[time_group+'__Second'][:][i], microsecond=nc_dataset[time_group+'__Second'][:][i]*1000), time_unit_out) 
+                                            for i in range(len(nc_dataset[time_group+'__Year'][:]))]
+
+    return new_time_list, time_unit_out
 
 def change_var_dims(nc_dataset, variables=None):
     """
@@ -62,4 +73,15 @@ def change_var_dims(nc_dataset, variables=None):
                 # copy the data to the new variable with dimension names
                 new_mapped_var[var_name][:] = var[:]
 
+    if not any("timeMidScan" in var for var in var_list):
+        scan_time_groups = ["__".join(i.split('__')[:-1]) for i in var_list if 'ScanTime' in i]
+        for time_group in list(set(scan_time_groups)):
+            time_data, time_unit = create_new_time_var(time_group, nc_dataset)
+            new_time_var_name = time_group+'__timeMidScan'
+            var_dims = nc_dataset.variables[time_group+'__Year'].dimensions
+            comp_args = {"zlib": True, "complevel": 1}
+            nc_dataset.createVariable(new_time_var_name, 'f8', var_dims, **comp_args)
+            nc_dataset.variables[new_time_var_name].setncattr('unit', time_unit)
+            nc_dataset.variables[new_time_var_name][:] = time_data
+
     return nc_dataset