add purge dialog

src/View/Geometry/Table.py

@@ -259,11 +259,11 @@ class GeometryReachTableModel(PamhyrTableModel):
         self.layoutAboutToBeChanged.emit()
         self.layoutChanged.emit()
 
-    def purge(self):
+    def purge(self, np_purge):
 
         self._undo.push(
             PurgeCommand(
-                self._data, 24
+                self._data, np_purge
             )
         )
         self.layoutChanged.emit()