在次轴上绘制两个变量时具有单个 y 轴值

Question

我正在尝试在使用主轴和副轴的图表中绘制三个变量，主轴上有一个变量，副轴上有两个变量。我的代码

vav = floor_data[floor_data['vavId'] == i]
        vav = vav.reset_index()
        x = vav.index 
        y1 = vav['nvo_temperature_sensor_pps']
        y2 = vav['nvo_airflow']
        y3 = vav['nvo_air_damper_position']   

        fig, ax1 = plt.subplots()
        ax2 = ax1.twinx()
        ax1.plot(x, y1, 'g-')
        ax2.plot(x, y2, 'b-')
        ax2.plot(x, y3, 'r-')
        ax2 = ax1.twinx()

        ax1.set_xlabel('VAV '+str(i))
        ax1.set_ylabel('temperature ', color='g')
        ax2.set_ylabel('air flow, temperature', color='b')

        plt.show()

我已经添加了所有三个变量，但我在次轴的 y 刻度中遇到问题。我的情节看起来像

是否可以在辅助轴上使用单个 y 刻度值以提高可读性？

Answer 1

您需要在主机上创建新的 twix 轴并缩小子图以在右侧为附加轴创建 space。然后在正确的位置移动新轴。代码中的一些描述。

import matplotlib.pyplot as plt
import numpy as np

fig, host = plt.subplots()
# shrink subplot
fig.subplots_adjust(right=0.75)

# create new axis on host
par1 = host.twinx()
par2 = host.twinx()
# place second axis at far right position
par2.spines["right"].set_position(("axes", 1.2))


# define plot functions
def function_sin(x):
    return np.sin(x)


def function_parabola(x):
    return x**2


def function_line(x):
    return x+1

# plot data
x = np.linspace(0, 10, 100)
y_sin = function_sin(x)
y_parabola = function_parabola(x)
y_line = function_line(x)
host.plot(x, y_sin, "b-")
par1.plot(x, y_parabola, "r-")
par2.plot(x, y_line, "g-")

# set labels for each axis
host.set_xlabel("VAV 16")
host.set_ylabel("Temperature")
par1.set_ylabel("Temperature")
par2.set_ylabel("Air Flow")

plt.show()

输出：

在次轴上绘制两个变量时具有单个 y 轴值

Having a single y axis values while plotting two variables on secondary axis

python

matplotlib

axis-labels

plotly