在matplotlib，Python中绘制几个图形

Question

I need to draw graphs in python matplotlib.

For each graph I do some calculates before and then draw the graphe. Here is some of the code:

import matplotlib.pyplot as plt

def draw(LuxCoordinates, finalPix, verName):
    plt.axes([0.2, 0.2, 0.7, 0.6]);
    plt.xlim(0,3500); #Axis x
    plt.ylim(0,100); #Axis y
    plt.plot(LuxCoordinates, finalPix, 'g');
    plt.scatter(LuxCoordinates, finalPix, linewidths=1)
    plt.grid(axis)
    plt.xlabel('X_Coordinates', color='r');
    plt.ylabel('Y_Coordinates', color='r');
    plt.title(verName, color='#afeeee');
    savefig(verName+'.png');
    plt.show();

My problem is that I call to this function twice or more, according to the number of graphs I have, I get the graphs in separate plots, but I want to draw all graphs on the same plot, in order to compare them. How can I do it? Thank you all!

Answer 1

remove plt.show()

your function should get a figure or axis as an input parameter, and do the plotting on that figure, and then outside the function when you have done all the plotting you may call plt.show()

here is a minimal example:

import matplotlib.pyplot as plt
import numpy as np

def plotter ( ax, col ):
    data = np.random.normal( size=(50, 2 ) )
    x, y = data[:, 0], data[:, 1 ]
    ax.scatter( x, y, color=col )

fig = plt.figure()
ax = fig.add_axes([0.2, 0.2, 0.7, 0.6])

plotter( ax, 'Blue' )
plotter( ax, 'Red' )
fig.show( )