鼠标悬停在数据上时如何显示数据标签

Question

我正在绘制一些看起来像的数据

931,Oxfordshire,9314125,123255,Larkmead School,Abingdon,125,124,20,SUPP,8
931,Oxfordshire,9314126,123256,John Mason School,Abingdon,164,164,25,6,16
931,Oxfordshire,9314127,123257,Fitzharrys School,Abingdon,150,149,9,0,11
931,Oxfordshire,9316076,123298,Our Lady's Abingdon,Abingdon,57,57,SUPP,SUPP,16

我的基本步骤是

df = pandas.read_csv("file.csv", names=['A','B','C','D','E','F','G', 'H','I','J', 'K'], header=None)
df.replace('SUPP', 3.0, inplace=True)
df = df.convert_objects(convert_numeric=True)
df['KG'] = df['K']*1.0/df['G']
plt.plot(result['KG'])
plt.show()

但是当我将鼠标悬停在图表上时,我真的想得到每所学校的名称,以便我可以探索数据.有没有办法做到这一点？

Answer 1

只是为了插入我自己的项目,请看看mpldatacursor:https://github.com/joferkington/mpldatacursor

作为一个基本的例子,只需通过电话datacursor(hover=True, point_labels=df['E'])就可以获得90%的成功.例如,上面的代码段:

from StringIO import StringIO
import pandas as pd
import matplotlib.pyplot as plt
from mpldatacursor import datacursor

f = StringIO(
"""931,Oxfordshire,9314125,123255,Larkmead School,Abingdon,125,124,20,SUPP,8
931,Oxfordshire,9314126,123256,John Mason School,Abingdon,164,164,25,6,16
931,Oxfordshire,9314127,123257,Fitzharrys School,Abingdon,150,149,9,0,11
931,Oxfordshire,9316076,123298,Our Lady's Abingdon,Abingdon,57,57,SUPP,SUPP,16
""")
df = pd.read_csv(f, names=['A','B','C','D','E','F','G', 'H','I','J', 'K'],
                 header=None)
df.replace('SUPP', 3.0, inplace=True)
df = df.convert_objects(convert_numeric=True)
df['KG'] = df['K']*1.0/df['G']
plt.plot(df['KG'], marker='o')

datacursor(hover=True, point_labels=df['E'])

plt.show()

每当线路悬停时我们都会得到一个弹出标签.

但是,根据设计,默认行为是在线圈悬停/点击时显示弹出窗口.因此,在使用该point_labels选项时,结果可能与您的想法不同:

如果您只希望在顶点悬停时显示弹出窗口,则可以使用与此类似的解决方法:(将会有一个选项,仅在下一个版本的顶点显示弹出窗口,因此此解决方法将来不会被要求.)

from StringIO import StringIO
import pandas as pd
import matplotlib.pyplot as plt
from mpldatacursor import datacursor

f = StringIO(
"""931,Oxfordshire,9314125,123255,Larkmead School,Abingdon,125,124,20,SUPP,8
931,Oxfordshire,9314126,123256,John Mason School,Abingdon,164,164,25,6,16
931,Oxfordshire,9314127,123257,Fitzharrys School,Abingdon,150,149,9,0,11
931,Oxfordshire,9316076,123298,Our Lady's Abingdon,Abingdon,57,57,SUPP,SUPP,16
""")
df = pd.read_csv(f, names=['A','B','C','D','E','F','G', 'H','I','J', 'K'],
                 header=None)
df.replace('SUPP', 3.0, inplace=True)
df = df.convert_objects(convert_numeric=True)
df['KG'] = df['K']*1.0/df['G']
plt.plot(df['KG'], marker='o')

l, = plt.plot(df['KG'], marker='o', linestyle='', visible=False)
datacursor(l, hover=True, point_labels=df['E'])

plt.show()

此外,您可能只想显示有问题的学校,而不是x,y坐标等.要更改此设置,请使用自定义formatter功能:

datacursor(l, hover=True, point_labels=df['E'],
           formatter=lambda **kwargs: kwargs['point_label'][0])

最后,你可能想要一个带有更高级箭头和不同相对位置的白色盒子:

datacursor(l, hover=True, point_labels=df['E'], bbox=dict(fc='white'),
           formatter=lambda **kwargs: kwargs['point_label'][0], xytext=(0, 25),
           arrowprops=dict(arrowstyle='simple', fc='white', alpha=0.5))

只是为了最后一个例子将它们组合成一个可运行的版本:

from StringIO import StringIO
import pandas as pd
import matplotlib.pyplot as plt
from mpldatacursor import datacursor

f = StringIO(
"""931,Oxfordshire,9314125,123255,Larkmead School,Abingdon,125,124,20,SUPP,8
931,Oxfordshire,9314126,123256,John Mason School,Abingdon,164,164,25,6,16
931,Oxfordshire,9314127,123257,Fitzharrys School,Abingdon,150,149,9,0,11
931,Oxfordshire,9316076,123298,Our Lady's Abingdon,Abingdon,57,57,SUPP,SUPP,16
""")
df = pd.read_csv(f, names=['A','B','C','D','E','F','G', 'H','I','J', 'K'],
                 header=None)
df.replace('SUPP', 3.0, inplace=True)
df = df.convert_objects(convert_numeric=True)
df['KG'] = df['K']*1.0/df['G']
plt.plot(df['KG'], marker='o')

l, = plt.plot(df['KG'], marker='o', linestyle='', visible=False)
datacursor(l, hover=True, point_labels=df['E'], bbox=dict(fc='white'),
           formatter=lambda **kwargs: kwargs['point_label'][0], xytext=(0, 25))

plt.show()