add horizontal line as well

app.py

@@ -97,6 +97,7 @@ value, aux = loss_fn(params)
 (cicle_plot,) = axes[0].plot(x, circle_fn(x), color="blue")
 (circle_perpendicular_plot,) = axes[0].plot(x, aux["perpendicular_circle_fn"](x), color="blue", linestyle="--")
 x_star, y_star = aux["x_star"], aux["y_star"]
+(x0_perpendicular_plot,) = axes[0].plot([0, 1], [y_star, y_star], color="black", linestyle="--")
 radius = aux["r"]
 axes[0].add_patch(plt.Circle((x_star, y_star), radius, fill=False))
 
@@ -123,6 +124,7 @@ with st.empty():
             cicle_plot.set_data(x, circle_fn(x))
             circle_perpendicular_plot.set_data(x, aux["perpendicular_circle_fn"](x))
             x_star, y_star = aux["x_star"], aux["y_star"]
+            x0_perpendicular_plot.set_data([0, 1], [y_star, y_star])
             radius = aux["r"]
             axes[0].add_patch(plt.Circle((x_star, y_star), radius, fill=False))