Update app.py

app.py

@@ -259,8 +259,25 @@ if not df_final.empty and source_choice == "(All)":
         )
 
 # ------------------- Output -------------------
-fig = plot_radar(df_final, grouped, chart_title)
+# fig = plot_radar(df_final, grouped, chart_title)
+# st.plotly_chart(fig, use_container_width=True)
+df_plot = df_final.copy()
+avg_label = None
+
+if not df_plot.empty:
+    cols = list(SKILL_GROUPS.keys()) if grouped else SKILLS
+    show_cohort_avg = st.toggle("Show cohort average (all students)", value=True)
+
+    if show_cohort_avg:
+        avg_vals = df_plot[cols].mean()
+        avg_row = {"label": "Average (All Students)"}
+        avg_row.update({k: float(avg_vals[k]) for k in cols})
+        df_plot = pd.concat([df_plot, pd.DataFrame([avg_row])], ignore_index=True)
+        avg_label = "Average (All Students)"
+
+fig = plot_radar(df_plot, grouped, chart_title, avg_label=avg_label)
 st.plotly_chart(fig, use_container_width=True)
+
 st.caption(f"{len(df_final)} line(s) aggregated." if not df_final.empty else "No data.")
 
 # ================== Dynamic Stage Summaries (only if student answered that week) ==================