precipfile = "/Users/bolvin/oc.197901.sg"
num_lon = 144
num_lat = 72

fileobj = open(precipfile, mode='rb')

data = np.fromfile (fileobj, dtype ='f')

data.byteswap(True)

datat = np.reshape(data, (num_lon, num_lat), order = 'FORTRAN')

datamasked = np.ma.masked_where(datat < 0.0, datat)

my_cmap = matplotlib.colors.LinearSegmentedColormap('my_colormap',uneven_rgb)

my_cmap.set_bad('k', 0.8)

plt.figure(figsize = (20,10))

mapproj = Basemap(projection = 'cyl', llcrnrlat=-90.0, llcrnrlon=0.0, urcrnrlat=90.0, urcrnrlon=360.0)

mapproj.drawcoastlines()
mapproj.drawcountries()
mapproj.drawparallels(np.array([-90.0,-60.0,-30.0, 0.0, 30.0, 60.0, 90.0]), labels=[0,0,0,0])
mapproj.drawmeridians(np.array([0.0, 90.0, 180.0, 270.0, 360.0]), labels=[0,0,0,0])


myplot = plt.imshow(datamasked.T, interpolation = 'nearest', cmap = my_cmap,
norm = matplotlib.colors.Normalize(vmin = 0.0, vmax = 20.0, clip = False),
extent = (0.0, 360.0, -90.0, 90.0))