Stacked area chart

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
import seaborn as sns
import bokeh

import random
from IPython.core.display import HTML
from bokeh.plotting.figure import Figure
from bokeh.plotting import figure, show, reset_output, save
from bokeh.io import output_notebook, output_file

output_notebook(hide_banner=True)

def hugo_safe_render(fig: Figure) -> HTML:
    """ Save bokeh plot as HTML and re-embed into notebook, so that it also renders in Hugo markdown. """
    reset_output()
    name = f'{random.getrandbits(32)}.html'
    output_file(name)
    _ = save(fig)
    
    return HTML(f'<embed type="text/html" src="{name}" width="100%" height="{int(fig.height+100)}"></embed>')

x = pd.date_range('2020-01-01', '2020-01-31')
y = np.sin(range(len(x)))

df = pd.DataFrame({
    'sin': np.sin(range(len(x))) + 1,
    'cos': np.cos(range(len(x))) + 1,
    '2sin': (np.sin(range(len(x))) + 1) * 2,
}, index=x)

df.head()

df.plot.area();

from bokeh.palettes import brewer
from bokeh.plotting import figure, show
from bokeh.io import output_notebook
from bokeh.models import DataRange1d, HoverTool, DatetimeTickFormatter

output_notebook(hide_banner=True)

fig = figure(
    plot_height=200,
    sizing_mode='scale_width',
    x_axis_type='datetime',
    # get rid of gap on x-axis
    x_range=DataRange1d(start=x.min(), end=x.max())
)

names = df.columns.tolist()

fig.varea_stack(
    stackers=names,
    x='index',
    color=brewer['Spectral'][3],
    legend_label=names,
    source=df
)

# workaround for using HoverTool → https://stackoverflow.com/a/60895524/4866803
fig.vline_stack(
    stackers=names,
    x='index',
    color=brewer['Spectral'][3],
    legend_label=names,
    source=df
)

fig.grid.minor_grid_line_color = '#eeeeee'
fig.legend.orientation = "horizontal"
fig.legend.background_fill_color = "#fafafa"
fig.xaxis.formatter = DatetimeTickFormatter(
    months=['%b %Y'],
    days=['%b %d']
)

fig.add_tools(HoverTool(
    tooltips=[
        ('Date', '@index{%F}'),
        ('Name', '$name'),
        ('Value', '@$name')
    ],
    formatters={'@index': 'datetime'},
    ))

hugo_safe_render(fig)

norm_df = df.apply(lambda x: x/x.sum(), axis=1)
norm_df.head()

norm_df.plot.area();

from bokeh.plotting.figure import Figure

def bokeh_normalized_area_chart(df: pd.DataFrame) -> Figure:
    """ Use bokeh to plot a normalized stack area chart.
    
    Notes
    - Tooltips on hover
    - Expects df with DateTimeIndex and dimensions as columns

    """
    
    from bokeh.palettes import brewer
    from bokeh.plotting import figure, show
    from bokeh.io import output_notebook
    from bokeh.models import DataRange1d, HoverTool, DatetimeTickFormatter, NumeralTickFormatter, Legend

    output_notebook(hide_banner=True)

    fig = figure(
        plot_height=200,
        sizing_mode='scale_width',
        x_axis_type='datetime',
        # get rid of gap on x-axis
        x_range=DataRange1d(start=df.index.min(), end=df.index.max()),
        y_range=DataRange1d(start=0, end=1)
    )
    
    legend = Legend()
    fig.add_layout(legend, 'right')
    fig.legend.orientation = 'vertical'
    fig.legend.location = 'top_left'
    fig.legend.label_text_font_size = '8pt'
    fig.legend.background_fill_color = "#fafafa"

    names = df.columns.tolist()

    fig.varea_stack(
        stackers=names,
        x='index',
        color=brewer['Spectral'][len(names)],
        legend_label=names,
        source=df
    )

    # workaround for using HoverTool → https://stackoverflow.com/a/60895524/4866803
    fig.vline_stack(
        stackers=names,
        x='index',
        color=brewer['Spectral'][len(names)],
        legend_label=names,
        source=df
    )
    

    fig.grid.minor_grid_line_color = '#eeeeee'
    
    fig.xaxis.formatter = DatetimeTickFormatter(
        months=['%b %Y'],
        days=['%b %d']
    )
    
    fig.yaxis.formatter = NumeralTickFormatter(format='0 %')

    fig.add_tools(HoverTool(
        tooltips=[
            ('Date', '@index{%F}'),
            ('Name', '$name'),
            ('Value', '@$name{%0.2f}')
        ],
        formatters={'@index': 'datetime', '@$name' : 'printf'}
        ))

    return fig

fig = bokeh_normalized_area_chart(norm_df)
hugo_safe_render(fig)