Use two scatterplots instead of n

zonnewaarneming.py

@@ -67,11 +67,13 @@ ax.set_ylabel("Signaalsterkte (ongekalibreerd)")
 fig.canvas.set_window_title('Live waarneming Dwingeloo radiotelescoop op 1330 MHz')
 ax.set_title('Live waarneming Dwingeloo radiotelescoop op 1330 MHz')
 
-
 prev_points = None
 separation = None
 maxsignal = 0.
 
+scatterplot_sun = ax.scatter([1,2,3], [4,5,6], s=3, color='black')
+scatterplot_cas = ax.scatter([1,2,3], [4,5,6], s=3, color='blue')
+
 while True:
     time.sleep(0.2)
     if signal == prev_signal:
@@ -88,21 +90,17 @@ while True:
     az = Angle(az + 180 * u.deg)
 
     color = 'black'
-    if SEPARATION_AZ:
-        dwl_altaz = AltAz(location=dwl, obstime=Time.now())
-        az_sun = get_sun(Time.now()).transform_to(dwl_altaz).az
-        az_cas = cas_a.transform_to(dwl_altaz).az
-        separation_sun = (az - az_sun).wrap_at(180*u.deg).degree * np.cos(el)
-        separation_cas = (az - az_cas).wrap_at(180*u.deg).degree * np.cos(el)
-        if abs(separation_sun) < abs(separation_cas):
-            separation = separation_sun
-        else:
-            separation = separation_cas
-            color = 'blue'
+    dwl_altaz = AltAz(location=dwl, obstime=Time.now())
+    az_sun = get_sun(Time.now()).transform_to(dwl_altaz).az
+    az_cas = cas_a.transform_to(dwl_altaz).az
+    separation_sun = (az - az_sun).wrap_at(180*u.deg).degree * np.cos(el)
+    separation_cas = (az - az_cas).wrap_at(180*u.deg).degree * np.cos(el)
+    if abs(separation_sun) < abs(separation_cas):
+        separation = separation_sun
+        scatterplot = scatterplot_sun
     else:
-        separation_sun = get_sun(Time.now()).separation(pos).deg
-        separation_cas = cas_a.separation(pos).deg
-        separation = min(separation_sun, separation_cas)
+        separation = separation_cas
+        scatterplot = scatterplot_cas
 
     print(signal, flush=True)
 
@@ -114,13 +112,15 @@ while True:
         print(f"Out of range, separation is {separation:.1f}")
         continue
 
+    scatter_data = scatterplot.get_offsets()
+    scatter_data = np.vstack((scatter_data, [separation, signal]))
+    scatterplot.set_offsets(scatter_data)
 
     if prev_points is not None:
         prev_points.remove()
-    ax.scatter([separation], [signal], s=3, color=color)
     prev_points = ax.scatter([separation], [signal], s=30, color='red')
     ax.set_ylim((3000, 1.3 * maxsignal))
 
     # show the plot
     plt.show()
-    plt.pause(0.0001) # <-- sets the current plot until refreshed
+    plt.pause(0.0001)