Create function `get_duration`

Trajectories/plot_traj.py

@@ -2,6 +2,7 @@
 
 import report_graph
 import random
+import numpy as np
 
 def get_extr_coord(traj, e_overestim, SHPC, orientation):
     """Get the coordinates of the extrema of instantaneous eddies along a
@@ -37,6 +38,18 @@ def plot_single_traj(traj, e_overestim, SHPC, orientation, ax, src_crs,
                     xytext = (3 * random.random(), 3 * random.random()),
                     textcoords = "offset points")
 
+def get_duration(expanded_traj, e_overestim):
+    duration_list = []
+
+    for traj in expanded_traj:
+        init_date = report_graph.node_to_date_eddy(traj[0], e_overestim,
+                                                   only_date = True)
+        final_date = report_graph.node_to_date_eddy(traj[- 1], e_overestim,
+                                                    only_date = True)
+        duration_list.append(final_date - init_date)
+
+    return np.array(duration_list)
+
 if __name__ == "__main__":
     import util_eddies
     import matplotlib.pyplot as plt