two (or more) graphs in one plot with different x-axis AND y-axis scales in python

Question

I want 3 graphs on one axes object, for example:

#example x- and y-data
x_values1=[1,2,3,4,5]
y_values1=[1,2,3,4,5]

x_values2=[-1000,-800,-600,-400,-200]
y_         


        

Answer 1

In this example, you can plot multiple lines in each x-y-axis, and legend each line.

import numpy as np
import matplotlib.pyplot as plt
X1 = np.arange(10)
X1 = np.stack([X1, X1])
Y1 = np.random.randint(1, 10, (2, 10))
X2 = np.arange(0, 1000, 200)
X2 = np.stack([X2, X2])
Y2 = np.random.randint(100, 200, (2, 5))


x_label_names = ['XXX', 'xxx']
y_label_names = ['YYY', 'yyy']
X1_legend_names = ['X1_legend1', 'X1_legend2']
X2_legend_names = ['X2_legend1', 'X2_legend2']


def plot_by_two_xaxis(X1, Y1, X2, Y2, x_label_names: list, y_label_names: list, X1_legend_names: list, X2_legend_names: list):
    fig = plt.figure()
    ax1s = []
    ax2s = []
    lines = []
    j = 0
    for i in range(len(X1)):
        j += 1
        ax1s.append(fig.add_subplot(111, label=f"{j}", frame_on=(j == 1)))
    for i in range(len(X2)):
        j += 1
        ax2s.append(fig.add_subplot(111, label=f"{j}", frame_on=(j == 1)))

    k = 0
    for i in range(len(X1)):
        lines.append(ax1s[i].plot(X1[i], Y1[i], color=f"C{k}")[0])
        if i == 0:
            ax1s[i].set_xlabel(x_label_names[0], color=f"C{k}")
            ax1s[i].set_ylabel(y_label_names[0], color=f"C{k}")
            ax1s[i].tick_params(axis='x', colors=f"C{k}")
            ax1s[i].tick_params(axis='y', colors=f"C{k}")
        else:
            ax1s[i].set_xticks([])
            ax1s[i].set_yticks([])
        k += 1

    for i in range(len(X1)):
        lines.append(ax2s[i].plot(X2[i], Y2[i], color=f"C{k}")[0])
        if i == 0:
            ax2s[i].xaxis.tick_top()
            ax2s[i].yaxis.tick_right()
            ax2s[i].set_xlabel(x_label_names[1], color=f"C{k}")
            ax2s[i].set_ylabel(y_label_names[1], color=f"C{k}")
            ax2s[i].xaxis.set_label_position('top')
            ax2s[i].yaxis.set_label_position('right')
            ax2s[i].tick_params(axis='x', colors=f"C{k}")
            ax2s[i].tick_params(axis='y', colors=f"C{k}")
        else:
            ax2s[i].set_xticks([])
            ax2s[i].set_yticks([])
        k += 1

    ax1s[0].legend(lines, X1_legend_names + X2_legend_names)

    plt.show()


plot_by_two_xaxis(X1, Y1, X2, Y2, x_label_names,
                y_label_names, X1_legend_names, X2_legend_names)