Unlike 'plot', 'plot_date' does not completely honor the
> linestyle specification if given in a dictionary. Try this:
> import pylab l=dict(linestyle='-')
> pylab.plot_date([100000,200000,300000],[1,2,3],**l)
> You will see points as well as lines plotted. I suspect a
> small bug here?
There is a slight inconsistency in that plot_date and plot have
different default behavior, you can control the plot_date marker with
the dictionary; note that the linestyle and marker are independent
line properties.
# use no marker
l=dict(linestyle='-', marker=None)
# use a square marker
l=dict(linestyle='-', marker='s')
JDH