Changing markers on line

Have a lot of data, and when looking at full view I'd

    > like no markers, but when zoom in to see individual
    > points I'd like to place markers on the graph. Planing
    > on attaching some code to events to toggle markers on my
    > line. Is there a way to change the markers a line uses
    > after it has been plotted, or do I have to clear the plot
    > and replot?

Here is some example code that changes the marker style based on zoom
level. I wrote the example initially to show how to clip data from a
line based on zoom, but it also changes the marker style based on
number of points in the view window

Clip a line according to the current xlimits, and change the marker
style when zoomed in

from matplotlib.lines import Line2D
import matplotlib.numerix as nx
from pylab import figure, show

class ClippedLine(Line2D):
    Clip the xlimits to the axes view limits -- this example assumes x is sorted

    def __init__(self, ax, *args, **kwargs):
        Line2D.__init__(self, *args, **kwargs) = ax

    def set_data(self, *args, **kwargs):
        Line2D.set_data(self, *args, **kwargs)
        self.xorig = nx.array(self._x)
        self.yorig = nx.array(self._y)
    def draw(self, renderer):
        xlim =

        ind0, ind1 = nx.searchsorted(self.xorig, xlim)
        self._x = self.xorig[ind0:ind1]
        self._y = self.yorig[ind0:ind1]
        N = len(self._x)
        if N<1000:
            self._marker = 's'
            self._linestyle = '-'
            self._marker = None
            self._linestyle = '-'
        Line2D.draw(self, renderer)

fig = figure()
ax = fig.add_subplot(111, autoscale_on=False)

t = nx.arange(0.0, 100.0, 0.01)
s = nx.sin(2*nx.pi*t)
line = ClippedLine(ax, t, s, color='g', ls='-', lw=2)