python - bqplot:性能问题

Question

我正在尝试 bqplot 的 on_drag 功能。我注意到它有点滞后..我不确定这是否是

• 真正的问题
• 我做了一些不恰当的事情
• 按照本来的样子工作

所以我的代码如下

from bqplot import pyplot as plt
import numpy as np
fig=plt.figure()
lin=plt.plot([0,1],
             [0,0])
scatt1=plt.scatter([0],[0],colors=['Red'])
scatt2=plt.scatter([1],[0],enable_move=True)

plt.xlim(-3,3)
plt.ylim(-3,3)
fig.layout.height = '500px'
fig.layout.width = '500px'
plt.show()
def call_back2(name, value):
   #print(value,name)
   if value['point']:
       X=value['point']['x']
       Y=value['point']['y']
       lin.x=[scatt1.x[0],(X-scatt1.x)[0]]
       lin.y=[scatt1.y[0],(Y-scatt1.y)[0]]

scatt2.on_drag_start(call_back2)
scatt2.on_drag(call_back2)
scatt2.on_drag_end(call_back2)

这只是连接的两个点你可以拖动蓝色的我注意到这条线稍微落后于蓝点。

Answer 1

您不能直接拖动线上的点。您的方法是我所知道的唯一方法，因此该线将始终跟随散点。我无法让您的代码运行得明显更快。

from bqplot import pyplot as plt
import numpy as np
fig = plt.figure()
lin=plt.plot([0,1],
             [0,0])
scatt1=plt.scatter([0],[0],colors=['Red'])
scatt2=plt.scatter([1],[0],enable_move=True)
# scatt2.update_on_move = True

plt.xlim(-3,3)
plt.ylim(-3,3)
fig.layout.height = '500px'
fig.layout.width = '500px'
plt.show()
def call_back2(name, value):
#     with lin.hold_sync():
   lin.x=[lin.x[0], value['point']['x']]
   lin.y=[lin.y[0], value['point']['y']]    

# scatt2.on_drag_start(call_back2)
scatt2.on_drag(call_back2 )
# scatt2.on_drag_end(call_back2)

编辑:

其实是可以做到的。使用jslink。这些性状必须具有相同的类型和长度/大小。在本例中，线条和散点标记的“x”和“y”特征是长度为 2 的数组。

from bqplot import pyplot as plt
from ipywidgets import jslink

fig = plt.figure()

# Strange bug when 1st point is 0,0. Red point flickers.  
lin=plt.plot([0.0001,1],
             [0.0001,0])   

scatt2=plt.scatter(lin.x, lin.y, enable_move = True, colors = ['Red','blue'])
scatt2.update_on_move = True

# Cover up 1st point so it can't be moved. 
# Just remove this line if you want both points to be moveable
scatt3=plt.scatter([lin.x[0]], [lin.y[0]], colors = ['Red']) 


plt.xlim(-3,3)
plt.ylim(-3,3)
fig.layout.height = '500px'
fig.layout.width = '500px'
plt.show()

jslink((scatt2, 'x'), (lin, 'x'))
jslink((scatt2, 'y'), (lin, 'y'))

Jslink 不需要 Python 内核即可实现交互性。您可以通过以下方式创建 html 文件(和 js 目录):

import ipyvolume.embed
ipyvolume.embed.embed_html("bqplot.html", fig, offline=True, devmode=False)