如何使用 subplot2grid 自定义子图中的每个轴？

Question

I'm running some tests with a csv file I made up, with the following code

import matplotlib.pyplot as plt
import pandas as pd
from matplotlib import dates as mpl_dates

data = pd.read_csv('teste_csvread_panda.csv')
data['date'] = pd.to_datetime(data['date'])
data.sort_values('date', inplace=True)
date = data['date']
temp = data['temp']
sal = data['sal']

ax1 = plt.subplot2grid((2,1), (0,0), rowspan=1, colspan=1)
ax2 = plt.subplot2grid((2,1), (1,0), rowspan=1, colspan=1)

ax1.plot(date,temp, marker='.', label='temp')
ax1.legend(loc='upper right')
date_format = mpl_dates.DateFormatter('%b %d')
plt.gca().xaxis.set_major_formatter(date_format)

ax2.plot(date,sal, marker='.', label='sal')
ax2.legend(loc='lower left')
plt.gca().xaxis.set_major_formatter(date_format)

plt.show()

resulting plot here .

I would like to format the date axis for both subplots, but clearly it's working only for the last subplot. How can I make this happen?

Thank you in advance.

Answer 1

This should work. You need to define which axis is the current axis. I used plt.sca(ax) to do that at the beginning of each plot.

ax1 = plt.subplot2grid((2,1), (0,0), rowspan=1, colspan=1)
ax2 = plt.subplot2grid((2,1), (1,0), rowspan=1, colspan=1)

plt.sca(ax1)
plt.plot(date,temp, marker='.', label='temp')
plt.legend(loc='upper right')
date_format = mpl_dates.DateFormatter('%b %d')
plt.gca().xaxis.set_major_formatter(date_format)

plt.sca(ax2)
plt.plot(date, sal, marker='.', label='sal')
plt.legend(loc='lower left')
plt.gca().xaxis.set_major_formatter(date_format)

plt.show()