matplotlib-users Mailing List for matplotlib

Hi,
I'm having a problem using matplotlibs barbs function. I'm trying to 
plot some wind barbs on a map created with basemap. My code is as follows,

    m =
    Basemap(llcrnrlon=-35.0,llcrnrlat=40.0,urcrnrlon=10.0,urcrnrlat=68.0,
                 resolution='i',projection='lcc',lon_0=-12.5,lat_0=54.0)

    m.drawcoastlines()
    m.bluemarble()
    m.drawcoastlines()
    # draw parallels
    m.drawparallels(np.arange(40,68,5),labels=[1,0,0,0])
    # draw meridians
    m.drawmeridians(np.arange(-35, 10, 5),labels=[0,0,0,1])

    x, y = m(lons, lats)
    m.barbs(lons,lats,us,vs, barbcolor = 'r', flagcolor = 'r')
    plt.show()


where x, y, us and vs are lists with shape (64,). I get the following error,

    ERROR: An unexpected error occurred while tokenizing input
    The following traceback may be corrupted or invalid
    The error message is: ('EOF in multi-line statement', (382, 0))

    ---------------------------------------------------------------------------
    ValueError                                Traceback (most recent
    call last)

    /home/davcra/python_scripts/plot_synops.py in <module>()
          63 #m.plot(x,y,'ro', ms=5)

          64 plt.suptitle(record['date'])
    ---> 65 m.barbs(x,y,us,vs, barbcolor = 'r', flagcolor = 'r')
          66 #m.xlim(-35.0, 10.0)

          67 #m.ylim(40.0, 68.0)


    /usr/lib64/python2.6/site-packages/mpl_toolkits/basemap/__init__.pyc
    in barbs(self, x, y, u, v, *args, **kwargs)
        2924             retnh =  ax.barbs(x,y,unh,vnh,*args,**kwargs)
        2925             kwargs['flip_barb']=True
    -> 2926             retsh =  ax.barbs(x,y,ush,vsh,*args,**kwargs)
        2927             try:
        2928                 plt.draw_if_interactive()

    /usr/lib64/python2.6/site-packages/matplotlib/axes.pyc in
    barbs(self, *args, **kw)
        5888         """
        5889         if not self._hold: self.cla()
    -> 5890         b = mquiver.Barbs(self, *args, **kw)
        5891         self.add_collection(b)
        5892         self.update_datalim(b.get_offsets())

    /usr/lib64/python2.6/site-packages/matplotlib/quiver.pyc in
    __init__(self, ax, *args, **kw)
         776         self.set_transform(transforms.IdentityTransform())
         777
    --> 778         self.set_UVC(u, v, c)
         779
         780     __init__.__doc__ = """

    /usr/lib64/python2.6/site-packages/matplotlib/quiver.pyc in
    set_UVC(self, U, V, C)
         952
         953     def set_UVC(self, U, V, C=None):
    --> 954         self.u = ma.masked_invalid(U, copy=False).ravel()
         955         self.v = ma.masked_invalid(V, copy=False).ravel()
         956         if C is not None:

    /usr/lib64/python2.6/site-packages/numpy/ma/core.pyc in
    masked_invalid(a, copy)
        1976     condition = ~(np.isfinite(a))
        1977     if hasattr(a, '_mask'):
    -> 1978         condition = mask_or(condition, a._mask)
        1979         cls = type(a)
        1980     else:

    /usr/lib64/python2.6/site-packages/numpy/ma/core.pyc in mask_or(m1,
    m2, copy, shrink)
        1383         _recursive_mask_or(m1, m2, newmask)
        1384         return newmask
    -> 1385     return make_mask(umath.logical_or(m1, m2), copy=copy,
    shrink=shrink)
        1386
        1387

    /usr/lib64/python2.6/site-packages/numpy/ma/core.pyc in make_mask(m,
    copy, shrink, flag, dtype)
        1265         # We won't return after this point to make sure we
    can shrink the mask

        1266         # Fill the mask in case there are missing data

    -> 1267         m = filled(m, True)
        1268         # Make sure the input dtype is valid

        1269         dtype = make_mask_descr(dtype)

    /usr/lib64/python2.6/site-packages/numpy/ma/core.pyc in filled(a,
    fill_value)
         406     """
         407     if hasattr(a, 'filled'):
    --> 408         return a.filled(fill_value)
         409     elif isinstance(a, ndarray):
         410         # Should we check for contiguity ? and
    a.flags['CONTIGUOUS']:


    /usr/lib64/python2.6/site-packages/numpy/ma/core.pyc in filled(self,
    fill_value)
        2929             result = self._data.copy()
        2930             try:
    -> 2931                 np.putmask(result, m, fill_value)
        2932             except (TypeError, AttributeError):
        2933                 fill_value = narray(fill_value, dtype=object)

    ValueError: putmask: mask and data must be the same size
    WARNING: Failure executing file: <plot_synops.py>

Anyone know whats going on here??
Thanks in advance,
D