import yt

# Load the dataset.
ds = yt.load("IsolatedGalaxy/galaxy0030/galaxy0030")

# Create a 15 kpc radius sphere, centered on the center of the sim volume
sp = ds.sphere("center", (15.0, "kpc"))

# Get the angular momentum vector for the sphere.
L = sp.quantities.angular_momentum_vector()

print(f"Angular momentum vector: {L}")

# Create an off-axis ProjectionPlot of density centered on the object with the L
# vector as its normal and a width of 25 kpc on a side
p = yt.ProjectionPlot(
    ds, L, fields=("gas", "density"), center=sp.center, width=(25, "kpc")
)
p.save()