在世界地图上绘制分类数据

Question

我有5个国家/地区的数据采用这种格式

____USA.csv____
    lats, long, users
    37.3264,    -117.1416,  5334,
    37.3264,    -117.1416,  435,

现在，我想在世界地图上的美国上显示此数据。 为此我尝试了。

from mpl_toolkits.basemap import Basemap
import matplotlib.pyplot as plt
import numpy as np

# read input csv file
filename = 'D:/22_sept_14/USA.csv'
lats=[]
lons=[]
population=[]
with open(filename) as f:
    reader = csv.reader(f)
    for row in reader:
        lats.append(float(row[0]))
        lons.append(float(row[1]))
        population.append(float(row[2]))



map = Basemap(projection='robin', resolution = 'l', area_thresh = 1000.0,
              lat_0=0, lon_0=-130)
map.drawcoastlines()
map.drawcountries()
map.fillcontinents(color = 'gray')
map.drawmapboundary()
map.drawmeridians(np.arange(0, 360, 30))
map.drawparallels(np.arange(-90, 90, 30))

min_marker_size = 2.5
for lon, lat,pop in zip(lons, lats, population):
    x,y = map(lon, lat)
    if pop>1000:
        color='ro'
    elif pop<1000:
        color='yo'
    msize = pop * .01* min_marker_size
    map.plot(x, y, color, markersize=msize,alpha=.3)

plt.show()

但是问题在于该方法仅在“圆”中绘制数据。 我还想要用定量信息/“数字”（字体大小与数据成比例）填充这些圆圈。 我怎样才能做到这一点 ？

出于测试目的，我尝试在map.plot之前包括此行（上述代码中的倒数第二行）

plt.text(lon,lat,'59%',fontsize=34,fontweight='bold',ha='center',va='center',color='b')

但是，即使这样做也无济于事，因为一旦我在代码中包含以上行，此行map.plot(x, y, color, markersize=msize,alpha=.3)无法给出其输出。 相反，我只能看到文本“ 59％”。 我既可以绘制圆圈，也可以绘制文本（即59％）。 但不是两个人都在一起。 为什么会这样呢？

Answer 1

这对我有用。 很好，但是现在还可以。

from mpl_toolkits.basemap import Basemap
import matplotlib.pyplot as plt
import numpy as np
import csv

mark_font=3
lats=lons=population=[]
filename = 'D:/22_sept_14/mvsf.csv'
with open(filename) as f:
    reader = csv.reader(f)
    for row in reader:
        lats.append(float(row[0]))
        lons.append(float(row[1]))
        population.append(float(row[2]))

m = Basemap(projection='robin', resolution = 'l', area_thresh = 10000.0,
              lat_0=0, lon_0=0)
m.drawcoastlines()
m.drawcountries()
m.fillcontinents(color = 'gray')
m.drawmapboundary(fill_color='aqua')
m.drawmeridians(np.arange(0, 360, 30))
m.drawparallels(np.arange(-90, 90, 30))
# fill continents, set lake color same as ocean color.
# draw parallels and meridians.
# label parallels on right and top
# meridians on bottom and left
parallels = np.arange(0.,81,10.)
# labels = [left,right,top,bottom]
m.drawparallels(parallels,labels=[False,True,True,False])
meridians = np.arange(10.,351.,20.)
m.drawmeridians(meridians,labels=[True,False,False,True])
# plot blue dot on Boulder, colorado and label it as such.
lon, lat = -100.237, 49.125 # Location of Boulder
# convert to map projection coords.
# Note that lon,lat can be scalars, lists or numpy arrays.
xpt,ypt = m(lon,lat)
# convert back to lat/lon
lonpt, latpt = m(xpt,ypt,inverse=True)
m.plot(xpt,ypt,'go',markersize=17*mark_font,alpha=.8)  # plot a blue dot there
# put some text next to the dot, offset a little bit
# (the offset is in map projection coordinates)
plt.text(xpt,ypt,'17%' , fontsize=17,color='w')


lon, lat = -104.237, 40.125 # Location of Boulder
# convert to map projection coords.
# Note that lon,lat can be scalars, lists or numpy arrays.
xpt,ypt = m(lon,lat)
# convert back to lat/lon
lonpt, latpt = m(xpt,ypt,inverse=True)
m.plot(xpt,ypt,'ro',markersize=16*mark_font,alpha=.8)  # plot a blue dot there
# put some text next to the dot, offset a little bit
# (the offset is in map projection coordinates)
plt.text(xpt,ypt,'16%' , fontsize=16,color='w')

plt.show()