clippedline.py

00001 """
Clip a line according to the current xlimits, and change the marker
style when zoomed in
"""

from matplotlib.lines import Line2D
import numpy as np
from pylab import figure, show

00010 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)
        self.ax = ax


    def set_data(self, *args, **kwargs):
        Line2D.set_data(self, *args, **kwargs)
        self.xorig = np.array(self._x)
        self.yorig = np.array(self._y)

    def draw(self, renderer):
        xlim = self.ax.get_xlim()

        ind0, ind1 = np.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 = '-'
        else:
            self._marker = None
            self._linestyle = '-'


        Line2D.draw(self, renderer)


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

t = np.arange(0.0, 100.0, 0.01)
s = np.sin(2*np.pi*t)
line = ClippedLine(ax, t, s, color='g', ls='-', lw=2)
ax.add_line(line)
ax.set_xlim(10,30)
ax.set_ylim(-1.1,1.1)
show()