fix

rowers/interactiveplots.py

@@ -199,6 +199,8 @@ def interactive_hr_piechart(df, rower, title, totalseconds=0):
     df = df.with_columns((pl.col("deltat")*pl.col("hr")).alias("deltat"))
 
     sumtimehr = df['deltat'].sum()
+    if sumtimehr == 0:
+        return "", "No HR data"
 
     if totalseconds == 0:
         totalseconds = sumtimehr