Problem with planetary vorticity about windspharm HOT 2 CLOSED

As far as I can tell there is no problem with this routine. I suspect you are using data upside down, note the documentation for windspharm.standard.VectorWind:

The latitude dimension must be oriented north-to-south.

Your latitude dimension must have 90N first and 90S last, otherwise gradients will be incorrect, as will planetary vorticity which is calculated for a north-south grid. Also note there are the functions order_latdim and reverse_latdim in windspharm.tools to assist with getting the order correct. I would strongly recommend checking any other code you have written using the standard interface to make sure you are inputting fields in the correct orientation (iris and cdms interfaces will do this for you automatically).

If you have the grid oriented correctly I believe the current code is correct, for example:

import numpy as np
import matplotlib.pyplot as plt
from windspharm.standard import VectorWind


# create a dummy VectorWind object, we'll only use planetaryvorticity() so values don't matter
u = v = np.random.rand(73, 144)
w = VectorWind(u, v, gridtype='regular')

# calculate planetary vorticity
pvrt = w.planetaryvorticity()

# plot planetary vorticity, remembering it is for a north-south input grid
lon = np.arange(0., 360., 2.5)
lat = np.linspace(90, -90, 73)
plt.pcolor(lon, lat, pvrt)
plt.axis([0, 360, -90, 90])
plt.xlabel('longitude / degrees east')
plt.ylabel('latitude / degrees north')
plt.show()

which produces this, which is as it should be:

from windspharm.

Closing this on the assumption that the given solution solved your problem.

from windspharm.