16

我想在地图上绘制一个图表,其中节点将由坐标(纬度,经度)定义并具有一些关联的值。

我已经能够在底图上将点绘制为散点图,但似乎无法找到如何在地图上绘制图形。

谢谢。

编辑:我添加了关于如何在底图上绘制点的代码。其中大部分是从本文中的代码改编而来

from mpl_toolkits.basemap import Basemap
from shapely.geometry import Point, MultiPoint
import pandas as pd
import matplotlib.pyplot as plt

m = Basemap(
        projection='merc',
        ellps = 'WGS84',
        llcrnrlon=-130,
        llcrnrlat=25,
        urcrnrlon=-60,
        urcrnrlat=50,
        lat_ts=0,
        resolution='i',
        suppress_ticks=True)

# Create Point objects in map coordinates from dataframe lon
# and lat values
# I have a dataframe of coordinates
map_points = pd.Series(
                [Point(m(mapped_x, mapped_y)) 
                 for mapped_x, mapped_y in zip(df['lon'],
                                               df['lat'])])
amre_points = MultiPoint(list(map_points.values)) 

plt.clf()
fig = plt.figure()
ax = fig.add_subplot(111, axisbg='w', frame_on=False)
fig.set_size_inches(18.5, 10.5)

# Create a scatterplot on the map
dev = m.scatter(
            [geom.x for geom in map_points],
            [geom.y for geom in map_points],
            20, marker='o', lw=.25,
            facecolor='#33ccff', edgecolor='w',
            alpha=0.9,antialiased=True,
            zorder=3)

m.fillcontinents(color='#555555')

我得到这张图片: 地图

4

2 回答 2

18

这是一种方法:

import networkx as nx
import matplotlib.pyplot as plt
from mpl_toolkits.basemap import Basemap as Basemap
m = Basemap(
        projection='merc',
        llcrnrlon=-130,
        llcrnrlat=25,
        urcrnrlon=-60,
        urcrnrlat=50,
        lat_ts=0,
        resolution='i',
        suppress_ticks=True)

# position in decimal lat/lon
lats=[37.96,42.82]
lons=[-121.29,-73.95]
# convert lat and lon to map projection
mx,my=m(lons,lats)

# The NetworkX part
# put map projection coordinates in pos dictionary
G=nx.Graph()
G.add_edge('a','b')
pos={}
pos['a']=(mx[0],my[0])
pos['b']=(mx[1],my[1])
# draw
nx.draw_networkx(G,pos,node_size=200,node_color='blue')

# Now draw the map
m.drawcountries()
m.drawstates()
m.bluemarble()
plt.title('How to get from point a to point b')
plt.show()

在此处输入图像描述

于 2013-11-12T19:46:05.443 回答
4

截至今天,底图有一个不错的替代品。Mplleaflet是一个受 mpld3 启发的库。它的绘图速度比底图更快,更易于使用,并允许在漂亮的交互式 openstreetmap 上可视化地理数据。输入可以是经度和纬度,库会自动正确投影数据。

输入字典 pos,其中节点(国家)是键,long lat 保存为值。

 pos = {u'Afghanistan': [66.00473365578554, 33.83523072784668],
 u'Aland': [19.944009818523348, 60.23133494165451],
 u'Albania': [20.04983396108883, 41.14244989474517],
 u'Algeria': [2.617323009197829, 28.158938494487625],
 .....

绘图很简单:

import mplleaflet

fig, ax = plt.subplots()

nx.draw_networkx_nodes(GG,pos=pos,node_size=10,node_color='red',edge_color='k',alpha=.5, with_labels=True)
nx.draw_networkx_edges(GG,pos=pos,edge_color='gray', alpha=.1)
nx.draw_networkx_labels(GG,pos, label_pos =10.3)

mplleaflet.display(fig=ax.figure)
于 2016-06-07T22:25:35.193 回答