draw state abbreviations in matplotlib basemap

Question

I am drawing some data on basemap and use state boundaries in the background using this piece of code:

from mpl_toolkits.basemap import Basemap, cm
# requires netcdf4-python (netcdf4-python.googlecode.com)
from netCDF4 import Dataset as NetCDFFile
import numpy as np
import matplotlib.pyplot as plt

# plot rainfall from NWS using special precipitation
# colormap used by the NWS, and included in basemap.

nc = NetCDFFile('../../../examples/nws_precip_conus_20061222.nc')
# data from http://water.weather.gov/precip/
prcpvar = nc.variables['amountofprecip']
data = 0.01*prcpvar[:]
latcorners = nc.variables['lat'][:]
loncorners = -nc.variables['lon'][:]
lon_0 = -nc.variables['true_lon'].getValue()
lat_0 = nc.variables['true_lat'].getValue()
# create figure and axes instances
fig = plt.figure(figsize=(8,8))
ax = fig.add_axes([0.1,0.1,0.8,0.8])
# create polar stereographic Basemap instance.
m = Basemap(projection='stere',lon_0=lon_0,lat_0=90.,lat_ts=lat_0,\
            llcrnrlat=latcorners[0],urcrnrlat=latcorners[2],\
            llcrnrlon=loncorners[0],urcrnrlon=loncorners[2],\
            rsphere=6371200.,resolution='l',area_thresh=10000)
# draw coastlines, state and country boundaries, edge of map.
m.drawcoastlines()
m.drawstates()
m.drawcountries()
plt.show()

Is it a way to draw state names on the map (e.g. CA for California)?

Answer 1

The @Serenity answer is right but where the Abbreviations should be placed should be changed manually for some small states (e.g. look at FL).

Instead of mean of all points of a state's polygon one could draw a convexhull over those points and use the average of those points. This wouldn't change things a lot but might be useful for someone.

Also there is a problem that some states have several small islands that we're not drawing them here (skipping those islands when short_name is in printed_names). In case of Michigan and Wisconsin, those Islands come before the main state so they're not drawn. I checked and the main Michigan is the number 4 and for Wisconsin the number 3, so we just draw the state name for 4th Michigan and for 3rd Wisonsin.

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.basemap import Basemap as Basemap
from matplotlib.patches import Polygon
from scipy.spatial import ConvexHull, Voronoi
import pdb

short_state_names = {
        'AK': 'Alaska',
        'AL': 'Alabama',
        'AR': 'Arkansas',
        'AS': 'American Samoa',
        'AZ': 'Arizona',
        'CA': 'California',
        'CO': 'Colorado',
        'CT': 'Connecticut',
        'DC': 'District of Columbia',
        'DE': 'Delaware',
        'FL': 'Florida',
        'GA': 'Georgia',
        'GU': 'Guam',
        'HI': 'Hawaii',
        'IA': 'Iowa',
        'ID': 'Idaho',
        'IL': 'Illinois',
        'IN': 'Indiana',
        'KS': 'Kansas',
        'KY': 'Kentucky',
        'LA': 'Louisiana',
        'MA': 'Massachusetts',
        'MD': 'Maryland',
        'ME': 'Maine',
        'MI': 'Michigan',
        'MN': 'Minnesota',
        'MO': 'Missouri',
        'MP': 'Northern Mariana Islands',
        'MS': 'Mississippi',
        'MT': 'Montana',
        'NA': 'National',
        'NC': 'North Carolina',
        'ND': 'North Dakota',
        'NE': 'Nebraska',
        'NH': 'New Hampshire',
        'NJ': 'New Jersey',
        'NM': 'New Mexico',
        'NV': 'Nevada',
        'NY': 'New York',
        'OH': 'Ohio',
        'OK': 'Oklahoma',
        'OR': 'Oregon',
        'PA': 'Pennsylvania',
        'PR': 'Puerto Rico',
        'RI': 'Rhode Island',
        'SC': 'South Carolina',
        'SD': 'South Dakota',
        'TN': 'Tennessee',
        'TX': 'Texas',
        'UT': 'Utah',
        'VA': 'Virginia',
        'VI': 'Virgin Islands',
        'VT': 'Vermont',
        'WA': 'Washington',
        'WI': 'Wisconsin',
        'WV': 'West Virginia',
        'WY': 'Wyoming'
}

m = Basemap(llcrnrlon=-119,llcrnrlat=22,urcrnrlon=-64,urcrnrlat=49,
            projection='lcc',lat_1=33,lat_2=45,lon_0=-95)
# data from U.S Census Bureau
# http://www.census.gov/geo/www/cob/st2000.html
shp_info = m.readshapefile('./data/us_states_st99/st99_d00','states',drawbounds=True)
printed_names = []
mi_index = 0
wi_index = 0
for shapedict,state in zip(m.states_info, m.states):
    draw_state_name = True
    short_name = short_state_names.keys()[short_state_names.values().index(shapedict['NAME'])]
    if short_name in printed_names and short_name not in ['MI', 'WI']: 
        continue
    if short_name == 'MI':
        if mi_index != 3:
            draw_state_name = False
        mi_index += 1
    if short_name == 'WI':
        if wi_index != 2:
            draw_state_name = False
        wi_index += 1
    # center of polygon
    x, y = np.array(state).mean(axis=0)
    hull = ConvexHull(state)
    hull_points = np.array(state)[hull.vertices]
    #center of convex hull over the polygon points
    x, y = hull_points.mean(axis=0)
    if draw_state_name:
        # You have to align x,y manually to avoid overlapping for little states
        plt.text(x+.1, y, short_name, ha="center")
    printed_names += [short_name,] 

m.drawparallels(np.arange(25,65,20),labels=[1,0,0,0])
m.drawmeridians(np.arange(-120,-40,20),labels=[0,0,0,1])
plt.title('The United States of North America')
plt.show()

If you care about other islands of other states you should do something similar with those islands (e.g. not to continue, draw the polygon but not the name, or whatever you need to do).

Answer 2

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

short_state_names = {
        'AK': 'Alaska',
        'AL': 'Alabama',
        'AR': 'Arkansas',
        'AS': 'American Samoa',
        'AZ': 'Arizona',
        'CA': 'California',
        'CO': 'Colorado',
        'CT': 'Connecticut',
        'DC': 'District of Columbia',
        'DE': 'Delaware',
        'FL': 'Florida',
        'GA': 'Georgia',
        'GU': 'Guam',
        'HI': 'Hawaii',
        'IA': 'Iowa',
        'ID': 'Idaho',
        'IL': 'Illinois',
        'IN': 'Indiana',
        'KS': 'Kansas',
        'KY': 'Kentucky',
        'LA': 'Louisiana',
        'MA': 'Massachusetts',
        'MD': 'Maryland',
        'ME': 'Maine',
        'MI': 'Michigan',
        'MN': 'Minnesota',
        'MO': 'Missouri',
        'MP': 'Northern Mariana Islands',
        'MS': 'Mississippi',
        'MT': 'Montana',
        'NA': 'National',
        'NC': 'North Carolina',
        'ND': 'North Dakota',
        'NE': 'Nebraska',
        'NH': 'New Hampshire',
        'NJ': 'New Jersey',
        'NM': 'New Mexico',
        'NV': 'Nevada',
        'NY': 'New York',
        'OH': 'Ohio',
        'OK': 'Oklahoma',
        'OR': 'Oregon',
        'PA': 'Pennsylvania',
        'PR': 'Puerto Rico',
        'RI': 'Rhode Island',
        'SC': 'South Carolina',
        'SD': 'South Dakota',
        'TN': 'Tennessee',
        'TX': 'Texas',
        'UT': 'Utah',
        'VA': 'Virginia',
        'VI': 'Virgin Islands',
        'VT': 'Vermont',
        'WA': 'Washington',
        'WI': 'Wisconsin',
        'WV': 'West Virginia',
        'WY': 'Wyoming'
}

m = Basemap(llcrnrlon=-119,llcrnrlat=22,urcrnrlon=-64,urcrnrlat=49,
            projection='lcc',lat_1=33,lat_2=45,lon_0=-95)
# data from U.S Census Bureau
# http://www.census.gov/geo/www/cob/st2000.html
shp_info = m.readshapefile('st99_d00','states',drawbounds=True)
printed_names = []
for shapedict,state in zip(m.states_info, m.states):
    short_name = short_state_names.keys()[short_state_names.values().index(shapedict['NAME'])]
    if short_name in printed_names: continue
    # center of polygon
    x, y = np.array(state).mean(axis=0)
    # You have to align x,y manually to avoid overlapping for little states
    plt.text(x+.1, y, short_name, ha="center")
    printed_names += [short_name,] 

m.drawparallels(np.arange(25,65,20),labels=[1,0,0,0])
m.drawmeridians(np.arange(-120,-40,20),labels=[0,0,0,1])
plt.title('The United States of North America')
plt.show()