獲取mpld3圖的縮放級別

Question

有沒有辦法讀出mpld3圖的縮放級別，即可見的x軸和y軸的範圍？ 我試圖使用d3.behavior.zoom，但我不知道如何獲得我的mpld3情節的縮放行爲。

Answer 1

您可以製作一個mpld3插件，使用我爲interactively adding callouts to scatter plots開發的模式進行此操作。這是簡單了很多，其實，所以它是一個簡單但很實用的插件的一個很好的例子：

import matplotlib.pyplot as plt, mpld3 
%matplotlib inline 

class ZoomSizePlugin(mpld3.plugins.PluginBase): 
    JAVASCRIPT = r""" 
    // little save icon 
    var my_icon = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAIAAACQkWg2AAAACXBIWXMAAAsTAAALEwEAmpwYAAAAB3RJTUUH3gUTDC0v7E0+LAAAAB1pVFh0Q29tbWVudAAAAAAAQ3JlYXRlZCB3aXRoIEdJTVBkLmUHAAAAa0lEQVQoz32QQRLAIAwCA///Mz3Y6cSG4EkjoAsk1VgAqspecVP3TTIA6MHTQ6sOHm7Zm4dWHcC4wc3hmVzT7xEbYf66dX/xnEOI7M9KYgie6qvW6ZH0grYOmQGOxzCEQn8C5k5mHAOrbeIBWLlaA3heUtcAAAAASUVORK5CYII="; 

    // create plugin 
    mpld3.register_plugin("zoomSize", ZoomSizePlugin); 
    ZoomSizePlugin.prototype = Object.create(mpld3.Plugin.prototype); 
    ZoomSizePlugin.prototype.constructor = ZoomSizePlugin; 
    ZoomSizePlugin.prototype.requiredProps = []; 
    ZoomSizePlugin.prototype.defaultProps = {} 

    function ZoomSizePlugin(fig, props){ 
     mpld3.Plugin.call(this, fig, props); 

     // create save button 
     var SaveButton = mpld3.ButtonFactory({ 
      buttonID: "save", 
      sticky: false, 
      onActivate: function(){save_zoom(fig);}.bind(this), 
      icon: function(){return my_icon;}, 
     }); 
     this.fig.buttons.push(SaveButton); 
    }; 

    function save_zoom(fig) { 
     var ax= fig.axes[0], 
      extent = ""; 
     extent = extent + "left=" + ax.x.invert(0); 
     extent = extent + ", right=" + ax.x.invert(ax.width); 
     extent = extent + ", bottom=" + ax.y.invert(ax.height); 
     extent = extent + ", top=" + ax.y.invert(0); 

     prompt("Copy extent of zoomed axis:", extent); 
    } 

    """ 

    def __init__(self): 
     self.dict_ = {"type": "zoomSize"} 

plt.plot([3,1,4,1,5,9,2,6,5,3,5,8], 'ks-', mew=1, mec='w') 
mpld3.plugins.connect(plt.gcf(), ZoomSizePlugin()) 
mpld3.display() 

對於我來說，它看起來像這樣：

這裏是a Jupyter Notebook version, if you want to play around。