我想知道如何在Python 3中保存FuncAnimation
的最后一个图像。这是一些代码:
import matplotlib.animation
from mpl_toolkits.mplot3d import Axes3D
ani = matplotlib.animation.FuncAnimation(fig, _update_2d_graph, frames=9, interval=600, repeat_delay=5000, blit=False)
ani.save(output_dir, writer="imagemagick")
其中_update_2d_graph
是根据帧号提供不同点偏移的函数:
def _update_2d_graph(num):
x_updated = np.hstack((pos_gt.x[:num].tolist(),pos_pred.x[:num].tolist()))
y_updated = np.hstack((pos_gt.y[:num].tolist(),pos_pred.y[:num].tolist()))
paths_gt = []
paths_ped = []
for i in range(num):
marker_gt = mmarkers.MarkerStyle('o')
marker_ped = mmarkers.MarkerStyle('x')
path_gt = marker_gt.get_path().transformed(marker_gt.get_transform())
path_ped = marker_ped.get_path().transformed(marker_ped.get_transform())
paths_gt.append(path_gt)
paths_ped.append(path_ped)
graph._paths = np.concatenate([paths_gt, paths_ped])
graph.set_facecolors(np.concatenate([colors[:num], colors[:num]]))
graph.set_edgecolors(np.concatenate([colors[:num], colors[:num]]))
graph.set_offsets(np.hstack((y_updated[:, np.newaxis], x_updated[:, np.newaxis])))
我不想保存整个动画(例如,保存为.gif文件),而是要保存动画最后一步的.png。 是否可以访问动画对象中的最后一帧?
我不想调用_update_2d_graph(9)
,因为动画对象已经执行了此调用,也不想通过另一个FuncAnimation
调用来重复整个9帧。
答案 0 :(得分:1)
实际上,我的初步测试表明,仅在运行动画后保存图形确实会保存最后的帧状态。您可以对其进行测试以确认吗?
ani = matplotlib.animation.FuncAnimation(fig, _update_2d_graph, frames=9, interval=600, repeat_delay=5000, blit=False)
ani.save(output_dir, writer="imagemagick")
fig.savefig('last_frame.png')
我使用了Animated 3D random walk example中的代码:
import numpy as np
import matplotlib.pyplot as plt
import mpl_toolkits.mplot3d.axes3d as p3
import matplotlib.animation as animation
# Fixing random state for reproducibility
np.random.seed(19680801)
def Gen_RandLine(length, dims=2):
"""
Create a line using a random walk algorithm
length is the number of points for the line.
dims is the number of dimensions the line has.
"""
lineData = np.empty((dims, length))
lineData[:, 0] = np.random.rand(dims)
for index in range(1, length):
# scaling the random numbers by 0.1 so
# movement is small compared to position.
# subtraction by 0.5 is to change the range to [-0.5, 0.5]
# to allow a line to move backwards.
step = ((np.random.rand(dims) - 0.5) * 0.1)
lineData[:, index] = lineData[:, index - 1] + step
return lineData
def update_lines(num, dataLines, lines):
for line, data in zip(lines, dataLines):
# NOTE: there is no .set_data() for 3 dim data...
line.set_data(data[0:2, :num])
line.set_3d_properties(data[2, :num])
return lines
# Attaching 3D axis to the figure
fig = plt.figure()
ax = p3.Axes3D(fig)
# Fifty lines of random 3-D lines
data = [Gen_RandLine(25, 3) for index in range(50)]
# Creating fifty line objects.
# NOTE: Can't pass empty arrays into 3d version of plot()
lines = [ax.plot(dat[0, 0:1], dat[1, 0:1], dat[2, 0:1])[0] for dat in data]
# Setting the axes properties
ax.set_xlim3d([0.0, 1.0])
ax.set_xlabel('X')
ax.set_ylim3d([0.0, 1.0])
ax.set_ylabel('Y')
ax.set_zlim3d([0.0, 1.0])
ax.set_zlabel('Z')
ax.set_title('3D Test')
# Creating the Animation object
line_ani = animation.FuncAnimation(fig, update_lines, 25, fargs=(data, lines),
interval=50, blit=False, repeat=True)
### HERE ARE THE ONLY LINES I ADDED ####
line_ani.save('./test.gif', writer='imagemagick')
fig.savefig('./test.png')
文件test.gif
文件test.png