[Matplotlib-users] Matplotlib drag overlapping points interactively

[Yi <ide...@gm...>]

Hi Matplotlib community:

In my case, I only want to drag one point each time. However, since the two
points are heavily overlapping, dragging one point would cause another
point to be dragged. How can I only drag one of the point? Thank you!


from pylab import *from scipy import *import matplotlib.pyplot as
pltimport matplotlib.patches as patches

class DraggablePoint:
    def __init__(self, p):
        self.point = p
        self.press = None

    def connect(self):
        self.cidpress =
self.point.figure.canvas.mpl_connect('button_press_event',
self.button_press_event)
        self.cidrelease =
self.point.figure.canvas.mpl_connect('button_release_event',
self.button_release_event)
        self.cidmotion =
self.point.figure.canvas.mpl_connect('motion_notify_event',
self.motion_notify_event)

    def disconnect(self):
    'disconnect all the stored connection ids'
        self.point.figure.canvas.mpl_disconnect(self.cidpress)
        self.point.figure.canvas.mpl_disconnect(self.cidrelease)
        self.point.figure.canvas.mpl_disconnect(self.cidmotion)


    def button_press_event(self,event):
        if event.inaxes != self.point.axes:
            return
        contains = self.point.contains(event)[0]
        if not contains: return
        self.press = self.point.center, event.xdata, event.ydata


    def button_release_event(self,event):
        self.press = None
        self.point.figure.canvas.draw()

    def motion_notify_event(self, event):
        if self.press is None: return
        if event.inaxes != self.point.axes: return
        self.point.center, xpress, ypress = self.press
        dx = event.xdata - xpress
        dy = event.ydata - ypress
        self.point.center = (self.point.center[0]+dx, self.point.center[1]+dy)
        print self.point.center
        self.point.figure.canvas.draw()
if __name__ == '__main__':
    fig = plt.figure()
    ax = fig.add_subplot(111)
    ax.set_xlim(-1,2)
    ax.set_ylim(-1,2)
    circles = []
    circle1 = patches.Circle((0.32,0.3), 0.2, fc='r', alpha=0.5, picker=True)
    circle = patches.Circle((0.3,0.3), 0.2, fc='b', alpha=0.5, picker=True)
    circles.append(ax.add_patch(circle1))
    circles.append(ax.add_patch(circle))
    drs = []
    for c in circles:
        #print c.center[0]
        dr = DraggablePoint(c)
        dr.connect()
        drs.append(dr)
    plt.show()