FuncAnimation Facecolor update not showing up until I resize

Community
1

Matplotlib Version - 3.5.2

I am using FuncAnimation for dynamic plotting. I also want to change the facecolor of particular regions of graphs as per the points. The color is getting changed, but only gets reflected when I resize the window.

Solution for the problem?

Attaching the code :-

fig = plt.figure()
ax1 = fig.add_subplot(1,1,1)

ax1.set_xlim(-10,10)
ax1.set_ylim(-10,10)

ax1.spines['left'].set_position('zero')
ax1.spines['bottom'].set_position('zero')

ax1.xaxis.label.set_color('white')       
ax1.yaxis.label.set_color('white')
ax1.tick_params(axis='x', colors='white')
ax1.tick_params(axis='y', colors='white')
# ax1.axvspan(0, 10, ymin=0.5, facecolor='red', alpha=0.5)
# ax1.axvspan(-10, 0, ymin=0.5, facecolor='green', alpha=0.5)
# ax1.axvspan(-10, 0, ymax=0.5, facecolor='black', alpha=0.5)
# ax1.axvspan(0, 10, ymax=0.5, facecolor='blue', alpha=0.5)

# ax1.set_facecolor('midnightblue')
t, = ax1.plot([], [], c='red', marker="o", ls="", alpha=1, label="Range Profile")
# a = 0
# b = 0
# c = 0
# d = 0

def readAndParseData():
    global detObj
    x = np.random.randint(-10,10,15)
    y = np.random.randint(-10,10,15)
    detObj = {"x": x, "z": y}

def func_init():
    # global a,b,c,d
    t.set_data([],[])
    # a = ax1.axvspan(-10, 0, ymin=0.5, facecolor='midnightblue')
    # b = ax1.axvspan(0, 10, ymax=0.5, facecolor='midnightblue')
    # c = ax1.axvspan(0, 10, ymin=0.5, facecolor='midnightblue')
    # d = ax1.axvspan(-10, 0, ymax=0.5, facecolor='midnightblue')

    return t,

def update(i):
    readAndParseData()
    z = detObj["z"]
    # print(z)
    # print("\n")
    x = detObj["x"]
    # y = detObj["y"]
    # print(x)

    # print(x)
    a = ax1.axvspan(-10, 0, ymin=0.5, facecolor='midnightblue')
    b = ax1.axvspan(0, 10, ymax=0.5, facecolor='midnightblue')
    c = ax1.axvspan(0, 10, ymin=0.5, facecolor='midnightblue')
    d = ax1.axvspan(-10, 0, ymax=0.5, facecolor='midnightblue')

    # ax1.axvspan(-10, 10, facecolor='midnightblue', alpha=1)

    for i in range(len(x)):
    
        if x[i]<0 and z[i]>=0:
            # a = ax1.axvspan(-10, 0, ymin=0.5, facecolor='lime', alpha=0.5)
            a.set_facecolor('lime')
            print(3)

        elif x[i]>=0 and z[i]<0:
            # b = ax1.axvspan(0, 10, ymax=0.5, facecolor='lime', alpha=0.5)
            b.set_facecolor('lime')
            print(1)

        elif x[i]>=0 and z[i]>=0:
            # c = ax1.axvspan(0, 10, ymin=0.5, facecolor='lime', alpha=0.5)
            c.set_facecolor('lime')
            print(2)

        else:
            # d = ax1.axvspan(-10, 0, ymax=0.5, facecolor='lime', alpha=0.5)
            d.set_facecolor('lime')
            print(4)


    t.set_data(x,z)

    return t,


ani = FuncAnimation(fig, update, init_func = func_init, interval=110, blit=True, save_count=0, cache_frame_data=False)

plt.show()

PS: In actuality, the readAndParseData() returns something else not random integers. I am making it return random integers for the sake of posting here…

2

The artists you want to update need to be returned from the update function (and probably should not be created in the update function).

If you set blit=False it will update promptly (at the cost of doing a full redraw).

3

That’s correct, blit=False works.

Thanks!