quiver plot in polar projection - how to make the quiver density latitude-dependent ? #6056
Description
Hello,
I want to do a quiver plot on a polar basemap plot. I have a regular lat/lon grid, and because there are more grid boxes at the higher latitudes, my code plots as many quivers at the pole as on the equator, so they overlap etc. How can I make the density of quivers latitude-dependent?
This is the code I use
import numpy as np
from mpl_toolkits.basemap import Basemap, addcyclic
import matplotlib.pyplot as plt
m_mu = Basemap(projection='npstere',boundinglat=10,lon_0=0,resolution='l',round=True)
lats=np.arange(0.,91.,15.)
lons=np.arange(-180.,181.,30.)
valin_u=np.array([[np.random.randn() for y in range(len(lons))] for x in range(len(lats))])
valin_v=np.array([[np.random.randn() for y in range(len(lons))] for x in range(len(lats))])
del x,y
valin = np.sqrt( valin_u**2 + valin_v**2 )
mu_cyclic, lons_cyclic = addcyclic(valin, lons)
mu_cyclic_u, lons_cyclic = addcyclic(valin_u, lons)
mu_cyclic_v, lons_cyclic = addcyclic(valin_v, lons)
grid = np.meshgrid( lons_cyclic, lats )
x, y = m_mu( *grid)
plt.figure()
cs = m_mu.pcolormesh(x, y, mu_cyclic)
#csquiv = m_mu.quiver(x[::3,::3], y[::3,::3], mu_cyclic_u[::3,::3], mu_cyclic_v[::3,::3])
csquiv = m_mu.quiver(x[::1,::1], y[::1,::1], mu_cyclic_u[::1,::1], mu_cyclic_v[::1,::1])
plt.show()
Many thanks for your help :-)
Sabine
