在matplotlib中的绘图数据之前绘制x轴上的年份

Question

我想预先绘制xaxis，使其包含5年，即2012,2013,2014,2015和2016.然后说我有两组数据，第一组是两个列表：

years1 = ['2012','2013']
scores1 = [0.2,0.3]

第二个也是两个列表，但与第一个列表的长度不同：

years2 = ['2013','2014','2015']
scores2 = [0.5,-0.4,0.8]

如何在python中使用matplotlib在一个图中绘制这两组数据？ x轴是预定的。

Answer 1

您只需拨打分散两次：

import matplotlib.pyplot as plt

years1_string = ['2012','2013']
years2_string = ['2013','2014','2015']

years1 = [int(i) for i in years1_string]
scores1 = [0.2,0.3]

years2 = [int(i) for i in years2_string]
scores2 = [0.5,-0.4,0.8]

fig, ax = plt.subplots(1)
ax.set_xlim(2012,2016)
ax.set_xticks([2012,2013,2014,2015,2016])
ax.scatter(years1, scores1, c='r', edgecolor=None, label = 'One')
ax.scatter(years2, scores2, c='b', edgecolor=None, label = 'Two')
ax.legend()
fig.show()

Answer 2

您不必预先确定xaxis。它会自动调整数据。如果您不想要，您当然可以手动设置限制或滴答。

然后，您可以将字符串转换为整数以进行绘图：

import matplotlib.pyplot as plt

years1 = ['2012','2013']
scores1 = [0.2,0.3]
years2 = ['2013','2014','2015']
scores2 = [0.5,-0.4,0.8]

#convert string list to integer list
y1 = list(map(int, years1))
y2 = list(map(int, years2))

plt.plot(y1, scores1, marker="o")
plt.plot(y2, scores2, marker="o")
plt.xticks(y1+y2)

plt. show()

但是，matplotlib可以很好地绘制字符串，只要它们可以转换为有意义的数字或日期。所以以下工作也很好。

import matplotlib.pyplot as plt

years1 = ['2012','2013']
scores1 = [0.2,0.3]
years2 = ['2013','2014','2015']
scores2 = [0.5,-0.4,0.8]

plt.plot(years1, scores1, marker="o")
plt.plot(years2, scores2, marker="o")
plt.xticks(range(2012,2016))

plt. show()