plot_vector(
    v, (x, -3, 3), (y, -3, 3),
    label="Magnitude of $%s$" % latex([-sin(y), cos(x)]),
    scalar=False, normalize=True,
    quiver_kw={
        "scale": 35, "headwidth": 4, "cmap": "gray",
        "clim": [0, 1.6]},
    grid=False, xlabel="x", ylabel="y")
# Expected:
## Plot object containing:
## [0]: 2D vector series: [sin(x - y), cos(x + y)] over (x, -3.0, 3.0), (y, -3.0, 3.0)