text: import yt
  
  # load the dataset
  ds = yt.load("IsolatedGalaxy/galaxy0030/galaxy0030")
  
  # This is an object that describes the entire box
  ad = ds.all_data()
  
  # We plot the average velocity magnitude (mass-weighted) in our object
  # as a function of density and temperature
  plot = yt.PhasePlot(
      ad, ("gas", "density"), ("gas", "temperature"), ("gas", "velocity_magnitude")
  )
  
  # save the plot
  plot.save()
  