There are four default styles of nodes.
import daft
pgm = daft.PGM(aspect=1.5, node_unit=1.75)
pgm.add_node("unobs", r"Unobserved!", 1, 4)
pgm.add_node("obs", r"Observed!", 1, 3, observed=True)
pgm.add_node("alt", r"Alternate!", 1, 2, alternate=True)
pgm.add_node("fixed", r"Fixed!", 1, 1, fixed=True, aspect=1.0, offset=[0, 5])
pgm.render()
<Axes: >