散点图未使用Managers进行多重处理

Question

This program shows no error yet it produces a blank plot without any points. I later on wish to modify this code so that many processes can work in parallel to change the shared matplotlib scatter plot.

from multiprocessing.managers import BaseManager, NamespaceProxy
from multiprocessing import Process
import matplotlib.pyplot as plt
import numpy as np

def plotter(res):
    print(res.ax,res.fig)
    res.ax.scatter(np.random.normal(0,20,(100,)),np.random.uniform(0,20,(100,)),s=1)
    res.fig.savefig('man2.png')


class PlotClass():
    fig = plt.figure()
    ax = fig.add_subplot(111)

    def __init__(self):
        print('Test') 


class MyManager(BaseManager):
    pass

class MyAttProxy(NamespaceProxy):
    # We need to expose the same __dunder__ methods as NamespaceProxy,
    _exposed_ = ('__getattribute__', '__setattr__', '__delattr__')

MyManager.register('Plot', PlotClass,MyAttProxy)

if __name__ == '__main__':
    manager = MyManager()
    manager.start()
    plotscat = manager.Plot()
    pr = Process(target=plotter,args=(plotscat,))
    pr.start()
    pr.join()
    plotscat.fig.savefig('fig.png')

Answer 1

Maybe you should re draw the figure after you add the scatter

def plotter(res):
    print(res.ax,res.fig)
    res.ax.scatter(np.random.normal(0,20,(100,)),np.random.uniform(0,20,(100,)),s=1)
    res.fig.canvas.draw_idle()
    res.fig.savefig('man2.png')