Merge pull request #43 from gisce/fix_filter_min_magn

Añadir validación de filtrado para magnitudes

powerprofile/powerprofile.py

@@ -277,21 +277,23 @@ def min(self, magn, ret='value', magn_0=None, force_magn_gt_0=False):
         :param ret: value or timestamp of minimum
         :return: min magnitude value
         """
-        filtered = self.curve.copy()
+        if self._check_magn_is_valid(magn):
+            filtered = self.curve.copy()
 
-        if force_magn_gt_0:
-            filtered = filtered[self.curve[magn] > 0]
-        if magn_0 is not None:
-            filtered = filtered[self.curve[magn_0] == 0]
+            if force_magn_gt_0:
+                filtered = filtered[self.curve[magn] > 0]
 
-        if self._check_magn_is_valid(magn):
-            if ret == 'value':
-                return filtered[magn].min()
-            elif ret == 'timestamp':
-                idx_min = filtered[magn].idxmin()
-                return self[idx_min][self.datetime_field]
+            if magn_0 is not None and self._check_magn_is_valid(magn_0):
+                filtered = filtered[self.curve[magn_0] == 0]
+
+            if not filtered.empty:
+                if ret == 'value':
+                    return filtered[magn].min()
+                elif ret == 'timestamp':
+                    idx_min = filtered[magn].idxmin()
+                    return self[idx_min][self.datetime_field]
 
-            return False
+        return False
 
     def avg(self, magn):
         """