CODEWITHSUNDEEP
pythonmatplotlib
George
George

Reputation: 157

Two figures opening, first one is empty

screen_width = 45
screen_height = 45

plt.rcParams["figure.figsize"] = (screen_width, screen_height)
plt.style.use('fivethirtyeight')
plt.tight_layout()

fig, (ax1, ax2) = plt.subplots(2,1)
ax1.set_title("Voltage vs samples")
ax1.grid()
ax1.set_ylabel("Voltage (V)")
ax1.set_xlabel("Samples")

ax2.set_title("Current vs samples")
ax2.set_ylabel("Current (A)")
ax2.set_xlabel("Samples")    
ax2.grid()

# animation def
def animate(i):
    plt.cla()
    ax1.plot(x_vals, y_vals, 'ro')
    ax2.plot(x_vals_1, y_vals_1, 'bo')
    plt.tight_layout

ani = FuncAnimation(fig, animate, interval=1000)

The code works somewhat. It does animate and update the data how I want it. However, it creates two figures, the first figure is empty and the second figure is the one being updated. Why is this the case?

Upvotes: 1

Views: 184

Answers (1)

William Miller
William Miller

Reputation: 10320

When plt.tight_layout() is called prior to the creation of a figure, one is created on-the-fly. To avoid the creation of this figure you can simply call plt.tight_layout() after creating a Figure instance, i.e.

# ...
fig, (ax1, ax2) = plt.subplots(2, 1)
plt.tight_layout()
# ...

Also note that the line 

def animate(i):
    # ...
    plt.tight_layout

Does nothing because the function is not called without the trailing parentheses. If you want to call tight_layout in your animate function it should be

def animate(i):
    # ...
    plt.tight_layout()

Upvotes: 3

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