add function to create subset

Author: AntSimi

src/py_eddy_tracker/observations/observation.py

@@ -29,7 +29,7 @@
 """
 from numpy import zeros, where, unique, \
     ma, cos, radians, isnan, ones, ndarray, \
-    floor, array, empty
+    floor, array, empty, absolute
 from netCDF4 import Dataset
 from ..generic import distance_grid, distance
 from .. import VAR_DESCR, VAR_DESCR_inv
@@ -100,8 +100,6 @@ def shifted_ellipsoid_degrees_mask2(lon0, lat0, lon1, lat1, minor=1.5, major=1.5
 
 @njit(cache=True, fastmath=True)
 def custom_concat(x, y):
-    '''
-    '''
     nb = x.shape[0]
     a = empty((nb,2))
     for i in range(nb):

src/py_eddy_tracker/observations/tracking.py

@@ -116,6 +116,20 @@ def set_global_attr_netcdf(self, h_nc):
         h_nc.time_coverage_start = d_start.strftime('%Y-%m-%dT00:00:00Z')
         h_nc.time_coverage_end = d_end.strftime('%Y-%m-%dT00:00:00Z')
 
+    def extract_with_period(self, period, **kwargs):
+        """
+        Extract with a period
+        Args:
+            period: two date to define period, must be specify from 1/1/1950
+            **kwargs: directly give to __extract_with_mask
+
+        Returns:
+            same object with selected data
+        """
+        mask = (self.time > period[0]) * (self.time < period[1])
+        return self.__extract_with_mask(mask, **kwargs)
+
+
     def __extract_with_mask(self, mask, full_path=False, remove_incomplete=False):
         """
         Extract a subset of observations