我制作了一张 basemap ,其中最大风速的位置根据风速绘制为绿色、黄色或红色。我现在尝试添加一个具有三种颜色的图例,但我收到此消息:
C:\Python27\lib\site-packages\matplotlib\axes.py:4747: UserWarning: 未找到标记的对象。在各个图上使用 label='...' kwarg。 warnings.warn(“未找到标记的对象。”
绘图输出正常,但没有图例。
非常感谢任何帮助。
#Produce map of North Atlantic with locations of maximum storm winds plotted
from mpl_toolkits.basemap import Basemap
#lat_0 and long_0 set the center of the map
plt.figure(3)
ax = plt.gca()
map1 = Basemap(projection='merc', lat_0 = 35, lon_0 = -40,
resolution = 'l', area_thresh = 1000.0, ax=ax,
#set the locations of the corners of the map
llcrnrlon=-85.0, llcrnrlat=0.0,
urcrnrlon=6.0, urcrnrlat=75.0)
map1.drawcoastlines()
map1.drawcountries()
map1.fillcontinents(color = 'coral')
map1.drawmapboundary()
#draw lines of longitude and latitude
map1.drawmeridians(np.arange(-80, 0, 10))
map1.drawparallels(np.arange(10, 70, 10))
#function to adjust colour depending on wind speed
def get_marker_colour(max_wind):
if max_wind < 20.0:
return ('go')
elif max_wind < 35.0:
return ('yo')
else:
return ('ro')
#Plotting data on the map
for lon, lat, wind in zip(alt_long_max, lat_max, max_wind):
x, y = map1(lon, lat)
marker_string = get_marker_colour(wind)
map1.plot(x, y, marker_string, markersize=4, markeredgewidth=0.0)
import matplotlib.patches as mpatches
low = mpatches.Patch(color='green', label='<20')
med = mpatches.Patch(color='yellow', label='20-35')
high = mpatches.Patch(color='red', label='>35')
plt.legend(handles=[low,med,high],title='Wind speed')
plt.title("Location of storm maximum winds")
plt.show()
最佳答案
这是您可以尝试的工作代码:
import matplotlib.patches as mpatches
from mpl_toolkits.basemap import Basemap
import numpy as np
import matplotlib.pyplot as plt
# color function
def colorf(wspeed):
if wspeed<20:
return 'green'
elif wspeed>35:
return 'red'
else:
return 'yellow'
pass
# make up some data
npts = 30
lon = np.linspace(91,99,npts)
lat = np.linspace(21,26,npts)
wspeed = np.linspace(10,60,npts) #wind speed 10-60
fig = plt.figure(figsize=(8,6))
ax = plt.gca()
bm = Basemap(llcrnrlon = 90, \
llcrnrlat = 20, \
urcrnrlon = 100, \
urcrnrlat = 30, \
projection='cyl', \
resolution='c', \
ax=ax)
# plot basic map features here
# plot storm path
for alon,alat,ws in zip(lon,lat,wspeed):
bm.plot(alon,alat, \
marker='o', \
markerfacecolor=colorf(ws), \
markersize=12)
#create legend
low = mpatches.Patch(color='green', label='<20')
med = mpatches.Patch(color='yellow', label='20-35')
high = mpatches.Patch(color='red', label='>35')
plt.legend(handles=[low,med,high], title='Wind speed')
plt.title("Location of storm maximum winds")
plt.show()
关于python - matplotlib 与点颜色对应的 basemap 图例,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/44006003/