@shoyer - This last commit (119c1c8) should have addressed the issues you brought up. I updated my examples a bit to show how things are working:

``` python %matplotlib inline import matplotlib.pyplot as plt import numpy as np import xray

sample DataArray

x = np.arange(start=0, stop=10, step=2) y = np.arange(start=9, stop=-7, step=-3) xy = np.dstack(np.meshgrid(x, y)) distance = np.linalg.norm(xy, axis=2) distance = xray.DataArray(distance, list(zip(('y', 'x'), (y, x))))

Sample plots

fig, axes = plt.subplots(3, 2, figsize=(8, 8), sharex=True, sharey=True) distance.plot(ax=axes[0, 0]) axes[0, 0].set_title('Default') distance.plot(vmin=0, vmax=12, levels=6, ax=axes[1, 0]) axes[1, 0].set_title('Setting with integer levels') distance.plot(levels=[1, 2, 4, 5, 7, 9], extend='max', cmap='Spectral', ax=axes[0, 1]) axes[0, 1].set_title('Setting with list of levels') flatui = ["#9b59b6", "#3498db", "#95a5a6", "#e74c3c", "#34495e", "#2ecc71"] distance.plot(levels=[1, 2, 4, 5, 7], cmap=flatui, extend='both', ax=axes[1, 1]) axes[1, 1].set_title('Using custom list of colors') distance.plot.contourf(ax=axes[2, 0]) axes[2, 0].set_title('Default contourf')

distance.plot.contourf(levels=4, ax=axes[2, 1]) axes[2, 1].set_title('contourf w/ int levels')

plt.tight_layout() ```

If the user sets the extend, vmax, or vmin arguments, those are not overridden. This is shown in the top right plot where I set extend='max' even though the min of the data is less than the min of levels. This results in the data less than the min of levels not being show. For the same reason, we also don't use the MaxNLocator if vmin or vmax was provided.