使用 pandas 根据另一列的值在地图上绘制数据框的选定列

Question

我是 python 编程新手。我有一个超过 1000 行的 csv 文件。我想根据地图上列（峰值电流）的值绘制列（纬度和经度）。每当我使用 pandas DataFrame 加载数据时，我通常会收到错误消息。但是，当我键入纬度和经度的值（前 10 个值）时，一切似乎都正常。尽管我无法根据数据框中的峰值电流为所选数据点绘制 lat/long。我想知道该怎么做。非常感谢任何帮助。

这是我的代码

from mpl_toolkits.basemap import Basemap
import matplotlib.lines as mlines
import matplotlib.pyplot as plt
from PIL import Image
import numpy as np
import pandas as pd

lon_0=2

#Loading data

#df = pd.read_csv('file.csv')
#lons = df['longitude']
#lat = df['latitude']

lons = [30.59294,30.593789,30.586066,30.648234,30.646268,30.633628,30.66251,29.531931,30.656409,30.708208]
lat = [-26.67026,-26.651906,-26.650199,-27.012214,-27.002663,-26.982482,-26.739707,-26.795177,-26.995863,-26.766377]

#coordinates
#llcrnrlat,llcrnrlon,urcrnrlat,urcrnrlon
# are the lat/lon values of the lower left and upper right corners of the map.
# lat_ts is the latitude of true scale.

m = Basemap(projection='geos',lon_0=lon_0,resolution='l',\
        llcrnrlat=-36,urcrnrlat=-21,llcrnrlon=15,urcrnrlon=34,)

m.drawcoastlines()
m.drawcountries()
m.drawstates()



# draw parallels and meridians.
parallels = np.arange(-90.,91.,5.)
# Label the meridians and parallels
m.drawparallels(parallels,labels=[False,True,True,False])
# Draw Meridians and Labels
meridians = np.arange(-180.,181.,10.)
m.drawmeridians(meridians,labels=[True,False,False,True])
m.drawmapboundary(fill_color='white')



x,y = m(lons, lat)
plt.plot(x, y, '*',markersize=5)

plt.show()

如果我取消注释下面的行以使用 pandas

加载数据，我通常会收到错误消息

#df = pd.read_csv('file.csv')
#lons = df['longitude']
#lat = df['latitude']

这是我要加载的部分数据

    timestamp                   latitude    longitude   peakcurrent icheight    numbersensors   majoraxis   minoraxis   bearing
 2016-01-07T19:00:00.206710100          -26.67026   30.59294    -38161         0            6     0.1          0.1      10.9
 2016-01-07T19:00:00.262988806          -26.651906  30.593789   -49949         0            6     0.1          0.1      13.9
 2016-01-07T19:00:00.387655020          -26.650199  30.586066   27485          0            6     0.51         0.24     10.9
 2016-01-07T19:00:02.242107391          -27.012214  30.648234   -39139         0            6     0.79         0.2      20.9
 2016-01-07T19:00:02.353171110          -27.002663  30.646268   53449          0            6     0.17         0.11     13.3
 2016-01-07T19:00:02.410721779          -26.982482  30.633628   -31396         0            6     0.95         0.64     33.9
 2016-01-07T19:00:02.446598530          -26.739707  30.66251    53774          0            6     0.66         0.12     13.5
 2016-01-07T19:00:02.452036619          -26.795177  29.531931   -36773         0            6     2            0.37     39
 2016-01-07T19:00:02.524655104          -26.995863  30.656409   33640          0            6     1.5          0.37     33.7
 2016-01-07T19:00:02.617701054          -26.766377  30.708208   -74489         0            7     1.23         0.37     21

Answer 1

您需要适当地获取 long 和 lat 的值。这是更正的相关代码。

# ...
lons = df.longitude.values  # needs .values here
lats = df.latitude.values   # same as above

x, y = m(lons, lats)
plt.plot(x, y, '*', markersize=60, zorder=20, alpha=0.3)

plt.show()

输出图将（使用示例数据）类似于：

使用 pandas 根据另一列的值在地图上绘制数据框的选定列

Issue plotting selected columns of a data-frame on a map based on the values of another column using pandas

python

csv

matplotlib

pandas

matplotlib-basemap