Python y Matplotlib y anotaciones con Mouse Hover

Question

Actualmente estoy empleando este código para tener anotaciones emergentes en un mapa cuando hago clic en un punto en un gráfico de Matplotlib del mapa base.

dcc = DataCursor(self.figure.gca()) 
self.figure.canvas.mpl_connect('pick_event',dcc) 
plot_handle.set_picker(5) 
self.figure.canvas.draw() 

class DataCursor(object): 

    import matplotlib.pyplot as plt 

    text_template = 'x: %0.2f\ny: %0.2f' 
    x, y = 0.0, 0.0 
    xoffset, yoffset = -20 , 20 
    text_template = 'A: %s\nB: %s\nC: %s' 


    def __init__(self, ax): 
     self.ax = ax 
     self.annotation = ax.annotate(self.text_template, 
       xy=(self.x, self.y), xytext=(0,0), 
       textcoords='axes fraction', ha='left', va='bottom', fontsize=10, 
       bbox=dict(boxstyle='round,pad=0.5', fc='yellow', alpha=1), 
       arrowprops=dict(arrowstyle='->', connectionstyle='arc3,rad=0') 
       ) 
     self.annotation.set_visible(False) 
     self.annotation.draggable() 


    def __call__(self, event): 

     self.event = event 
     self.x, self.y = event.mouseevent.xdata, event.mouseevent.ydata 

     if self.x is not None: 
      glim = pickle.load(open("ListA.py","rb")) 
      tlim = pickle.load(open("ListB.py","rb")) 
      vlim = pickle.load(open("ListC.py","rb")) 
      a = glim[event.ind[0]] # ['Name'][event.ind[0]] 
      b = tlim[event.ind[0]] 
      c = vlim[event.ind[0]] 
      temp_temp=self.text_template % (a, b, c) 
      if temp_temp == self.annotation.get_text() and self.annotation.get_visible(): 
       self.annotation.set_visible(False) 
       event.canvas.draw() 
       return 
      self.annotation.xy = self.x, self.y 
      self.annotation.set_text(self.text_template % (a, b, c)) 
      self.annotation.set_visible(True) 

      event.canvas.draw() 

Lo que estoy preguntando, es la forma de mostrar las anotaciones usando cursor del mouse en lugar de hacer clic en un punto?

He visto "motion_notify_event" pero parece que el código tiene errores cuando muevo el mouse por el área de trazado. ¿Alguna idea?

Answer 1

Tome un vistazo a this question y demo:

from matplotlib.pyplot import figure, show 
import numpy as npy 
from numpy.random import rand 


if 1: # picking on a scatter plot (matplotlib.collections.RegularPolyCollection) 

    x, y, c, s = rand(4, 100) 
    def onpick3(event): 
     ind = event.ind 
     print 'onpick3 scatter:', ind, npy.take(x, ind), npy.take(y, ind) 

    fig = figure() 
    ax1 = fig.add_subplot(111) 
    col = ax1.scatter(x, y, 100*s, c, picker=True) 
    #fig.savefig('pscoll.eps') 
    fig.canvas.mpl_connect('pick_event', onpick3) 

show() 

Answer 2

from mpl_toolkits.basemap import Basemap 
import matplotlib.pyplot as plt 

lat = 20.5937 
lon = 78.9629 
points_with_annotation = list() 

#Event is set for any movement and annotations are set to visible when on points with anotation 
def on_move(event): 
    visibility_changed = False 
    for point, annotation in points_with_annotation: 
     should_be_visible = (point.contains(event)[0] == True) 

     if should_be_visible != annotation.get_visible(): 
      visibility_changed = True 
      annotation.set_visible(should_be_visible) 

    if visibility_changed:   
     plt.draw() 


fig = plt.figure() 
ax = plt.axes() 

m = Basemap(projection='mill', llcrnrlat=-90, llcrnrlon=-180, urcrnrlat=90, urcrnrlon=180, resolution='c') 
m.fillcontinents(color='white', lake_color='white') 
m.drawcoastlines(linewidth=0.5, color='k') 
m.drawcountries(linewidth=0.5, color='k') 
m.drawmapboundary(fill_color='white') 

xpt, ypt = m(lon,lat) 
point, = m.plot(xpt, ypt, marker='o', markersize=5, alpha=0.85, visible=True) 
annotation = ax.annotate("Lat: %s Lon: %s" % (lat,lon), 
    xy=(xpt, ypt), xycoords='data', 
    xytext=(xpt + 1, ypt), textcoords='data', 
    horizontalalignment="left", 
    arrowprops=dict(arrowstyle="simple", 
    connectionstyle="arc3,rad=-0.2"), 
    bbox=dict(boxstyle="round", facecolor="w", 
    edgecolor="0.5", alpha=0.9) 
     ) 


annotation.set_visible(False) 
points_with_annotation.append([point, annotation]) 
on_move_id = fig.canvas.mpl_connect('motion_notify_event', on_move) 
plt.show() 

Aquí está el código para trazar una coordenada en un mapa y activar una ventana emergente durante el vuelo estacionario. Obtuve el código para el evento on_move de la respuesta a esta pregunta: Matplotlib basemap: Popup box Espero que esto ayude.