Matplotlib：删除单个标记

Question

I'm trying to plot a cdf with matplotlib. However, cdfs begin in the origin, thus I prepended zeros to the x and y arrays. The problem is now that the origin now is marked as a data point. I'd like to remove that single marker in the point (0,0).

Code and picture below.

#Part of the myplot (my own) class
def cdf(self):
    markers = ["x","v","o","^","8","s","p","+","D","*"]
    for index,item in enumerate(np.asarray(self.data).transpose()):
        x = np.sort(item)
        y = np.arange(1,len(x)+1) / len(x)
        x = np.insert(x,0,0)
        y = np.insert(y,0,0)
        self.plot = plt.plot(x,
                y,
                marker=markers[index],
                label=self.legend[index])
    self.setLabels( xlabel=self.xlabel,
                    ylabel="cumulative density",
                    title=self.title)
    self.ax.set_ylim(ymax=1)

Answer 1

You cannot remove a marker. What you may do is to plot all the markers first, then append the origin and then plot a line.

x = np.sort(item)
y = np.arange(1,len(x)+1) / len(x)
self.plot, = plt.plot(x, y, marker=markers[index], ls="", label=self.legend[index])
x = np.insert(x,0,0)
y = np.insert(y,0,0)
self.plot2, = plt.plot(x, y, marker="", color=self.plot.get_color())

Alternative: Use the markevery argument.

x = np.sort(item)
y = np.arange(1,len(x)+1) / len(x)
x = np.insert(x,0,0)
y = np.insert(y,0,0)
markevery = range(1, len(x))
self.plot, = plt.plot(x, y, marker=markers[index], markevery=markevery, 
                      ls="", label=self.legend[index])