# Make the output of plotting commands be displayed inline within the notebook,
%matplotlib inline 
from mpl_toolkits.basemap import Basemap  # import Basemap matplotlib toolkit
import numpy as np
import matplotlib.pyplot as plt
import pygrib # import pygrib interface to grib_api

grbs = pygrib.open('ecmwf_ensemble.grb')

for grb in grbs[:4]:
    print grb

print grb.keys()

grbs.rewind() # rewind the iterator
from datetime import datetime
date_valid = datetime(2014,2,3,0)
t2mens = []
for grb in grbs:
    if grb.validDate == date_valid and grb.parameterName == 'Temperature' and grb.level == 2: 
        t2mens.append(grb.values)
t2mens = np.array(t2mens)
print t2mens.shape, t2mens.min(), t2mens.max()
lats, lons = grb.latlons()  # get the lats and lons for the grid.
print 'min/max lat and lon',lats.min(), lats.max(), lons.min(), lons.max()

fig = plt.figure(figsize=(16,35))
m = Basemap(projection='lcc',lon_0=-74,lat_0=41,width=4.e6,height=4.e6)
x,y = m(lons,lats)
for nens in range(1,51):
    ax = plt.subplot(10,5,nens)
    m.drawcoastlines()
    cs = m.contourf(x,y,t2mens[nens],np.linspace(230,300,41),cmap=plt.cm.jet,extend='both')
    t = plt.title('ens member %s' % nens)

freezeprob = 100.*((t2mens < 273).sum(axis=0))/t2mens.shape[0]
print freezeprob.min(), freezeprob.max(), freezeprob.shape
m.drawcoastlines(color='r')
from mpl_toolkits.basemap import cm as basemapcm
cs = m.contourf(x,y,freezeprob,np.linspace(0,100.,41),cmap=basemapcm.GMT_haxby_r)
cb = m.colorbar()
xpt, ypt = m(-74,41)
nyc = m.plot([xpt],[ypt],'ro') # plot red dot near the Meadowlands.
t = plt.title('ens prob t2m < 273 (go Broncos!)')