matplotlib.github.com/1.5.3/pyplots/plotmap.py at main · matplotlib/matplotlib.github.com · GitHub

History

61 lines (55 loc) · 2.16 KB

Raw

import matplotlib.pyplot as plt

import numpy as np

try:

from mpl_toolkits.basemap import Basemap

have_basemap = True

except ImportError:

have_basemap = False

def plotmap():

# create figure

fig = plt.figure(figsize=(8,8))

# set up orthographic map projection with

# perspective of satellite looking down at 50N, 100W.

# use low resolution coastlines.

map = Basemap(projection='ortho',lat_0=50,lon_0=-100,resolution='l')

# lat/lon coordinates of five cities.

lats=[40.02,32.73,38.55,48.25,17.29]

lons=[-105.16,-117.16,-77.00,-114.21,-88.10]

cities=['Boulder, CO','San Diego, CA',

'Washington, DC','Whitefish, MT','Belize City, Belize']

# compute the native map projection coordinates for cities.

xc,yc = map(lons,lats)

# make up some data on a regular lat/lon grid.

nlats = 73; nlons = 145; delta = 2.*np.pi/(nlons-1)

lats = (0.5*np.pi-delta*np.indices((nlats,nlons))[0,:,:])

lons = (delta*np.indices((nlats,nlons))[1,:,:])

wave = 0.75*(np.sin(2.*lats)**8*np.cos(4.*lons))

mean = 0.5*np.cos(2.*lats)*((np.sin(2.*lats))**2 + 2.)

# compute native map projection coordinates of lat/lon grid.

# (convert lons and lats to degrees first)

x, y = map(lons*180./np.pi, lats*180./np.pi)

# draw map boundary

map.drawmapboundary(color="0.9")

# draw graticule (latitude and longitude grid lines)

map.drawmeridians(np.arange(0,360,30),color="0.9")

map.drawparallels(np.arange(-90,90,30),color="0.9")

# plot filled circles at the locations of the cities.

map.plot(xc,yc,'wo')

# plot the names of five cities.

for name,xpt,ypt in zip(cities,xc,yc):

plt.text(xpt+100000,ypt+100000,name,fontsize=9,color='w')

# contour data over the map.

cs = map.contour(x,y,wave+mean,15,linewidths=1.5)

# draw blue marble image in background.

# (downsample the image by 50% for speed)

map.bluemarble(scale=0.5)

def plotempty():

# create figure

fig = plt.figure(figsize=(8,8))

fig.text(0.5, 0.5, "Sorry, could not import Basemap",

horizontalalignment='center')

if have_basemap:

plotmap()

else:

plotempty()

plt.show()

matplotlib.github.com/1.5.3/pyplots/plotmap.py at main · matplotlib/matplotlib.github.com · GitHub

Expand file tree

Breadcrumbs

plotmap.py

Latest commit

History

Breadcrumbs

plotmap.py

File metadata and controls