Do not care about pressure when drawing hodographs

lib/xmet/hodograph.py

@@ -165,9 +165,6 @@ class Hodograph():
 
     def each_significant_sample(self, sounding: Sounding):
         for sample in sounding.samples:
-            if sample.pressure < 0 or sample.pressure is None:
-                continue
-
             if sample.height is None:
                 continue
 

lib/xmet/sounding.py

@@ -82,6 +82,18 @@ class Sounding(DatabaseTable):
         'data_source_pressure', 'data_source_other', 'samples', 'location'
     )
 
+    def __str__(self):
+        parts = [
+            f"Sounding from station {self.station}"
+        ]
+
+        if self.location is not None:
+            parts.append(f"(location {self.location})")
+
+        parts.append(f"observed {self.timestamp_observed}")
+
+        return ' '.join(parts)
+
     __table__ = 'xmet_sounding'
     __key__   = 'id'
 
@@ -118,6 +130,7 @@ class Sounding(DatabaseTable):
     def __init__(self):
         super().__init__()
         self.id       = None
+        self.location = None
 
     @staticmethod
     def valid_by_station(db: Database,