#!/usr/bin/env python
# coding: utf-8

# # Interactive auto-scaling candlestick plot in Jupyter Notebook with Bokeh

# In[1]:


from bokeh.io import output_notebook, show
from bokeh.plotting import figure
from bokeh.models import CustomJS, ColumnDataSource

output_notebook()

from functools import partial

# Set some figure defaults
figure = partial(figure,
                 plot_width=800,
                 plot_height=500,
                 responsive=False,
                 tools="pan,wheel_zoom,box_zoom,undo,redo,reset,crosshair,save",
                 active_drag='pan',
                 active_scroll='wheel_zoom')


# In[2]:


def candlestick_plot(df):
    fig = figure(x_axis_type='datetime')
    
    inc = df.Close > df.Open
    dec = ~inc
    width_ms = dict(day=86400,
                    hour=3600,
                    minute=60,
                    second=1)[df.index.resolution] * 1000 * .85
    
    fig.segment(df.index, df.High, df.index, df.Low, color="black")
    fig.vbar(df.index[inc], width_ms, df.Open[inc], df.Close[inc], fill_color="lime", line_color="black")
    fig.vbar(df.index[dec], width_ms, df.Open[dec], df.Close[dec], fill_color="tomato", line_color="black")
    
    source = ColumnDataSource(dict(index=df.index, x=df.Close))
    fig.x_range.callback = CustomJS(args=dict(y_range=fig.y_range, source=source), code='''
        clearTimeout(window._autoscale_timeout);
        
        var index = source.data.index,
            x = source.data.x,
            start = cb_obj.start,
            end = cb_obj.end,
            min = 1e10,
            max = -1;
        
        for (var i=0; i < index.length; ++i) {
            if (start <= index[i] && index[i] <= end) {
                max = Math.max(x[i], max);
                min = Math.min(x[i], min);
            }
        }
        var pad = (max - min) * .05;
        
        window._autoscale_timeout = setTimeout(function() {
            y_range.start = min - pad;
            y_range.end = max + pad;
        }, 50);
    ''')
    show(fig)


# In[3]:


import pandas_datareader.data as web

GOOG = web.DataReader('GOOG', 'google', '2015', '2018')
GOOG.head()


# In[4]:


candlestick_plot(GOOG)