Python Graphs

Some tricks collected from the SO and the web

Images

How to use an image as a background

import numpy as np
import matplotlib.pyplot as plt
np.random.seed(0)
x = np.random.uniform(0.0,10.0,15)
y = np.random.uniform(0.0,10.0,15)
datafile = 'lena.png'
img = plt.imread(datafile)
plt.scatter(x,y,zorder=1)
plt.imshow(img, zorder=0, extent=[0.5, 8.0, 1.0, 7.0])
plt.show()

caveat This requires you know where the image corners need to be!

sources:

• Plot over an image background in python
• Adding a background image to a plot with known corner coordinates

Creating a pictogram

import matplotlib.pyplot as plt
from pywaffle import Waffle
data = {'Democratic': 48, 'Republican': 46, 'Libertarian': 3}
fig = plt.figure(
    FigureClass=Waffle, 
    rows=5, 
    values=data, 
    colors=["#232066", "#983D3D", "#DCB732"],
    legend={'loc': 'upper left', 'bbox_to_anchor': (1, 1)},
    icons='child', 
    font_size=12, 
    icon_legend=True
)
plt.show()

note:

PyWaffle supports Font Awesome icons in the chart. plotly is an alternative. Sources: - How to make a pictogram / icon chart?

Add outline around flagged items in a plotly candlestick chart

import matplotlib.pyplot as plt
import numpy as np
import matplotlib.patches as mpatches
import pandas as pd
import plotly.graph_objects as go

df = pd.DataFrame({"data_minu": ['30/10 09:00','30/10 09:05','30/10,09:10','30/10 09:15','30/10 09:20','30/10 09:25','30/10 09:30','30/10 09:35','30/10 09:40','30/10 09:45'],
                   "Open":['10','17','23','20','8','22','24','25','29','22'],
                   "High":['21','27','25','29','24','27','28','32','29','25'],
                   "Low":['6','12','18','9','5','8','24','18','15','10'],
                   "Close":['17','24','22','10','21','25','26','30','18','10'],
                   "Flag": ['0','1','1','1','0','1','1','1','0','0']})     

tickvals = [k*0.5 for k in range(len(df))]
ticktext = list(df["data_minu"])

fig = go.Figure(data=[go.Candlestick(x=tickvals,
                open=df['Open'], high=df['High'],
                low=df['Low'], close=df['Close'])
                     ])  

fig.update_layout(xaxis_rangeslider_visible=False, xaxis_tickvals=tickvals, xaxis_ticktext=ticktext) 

for k, flag in enumerate(df['Flag']):
    if int(flag):
        fig.add_shape(dict(type='rect',
                          xref='x', yref='y',
                          layer='below', 
                          x0=tickvals[k]-0.2, y0=float(df.loc[k, 'Low'])-1,
                          x1=tickvals[k]+0.2, y1=float(df.loc[k, 'High'])+1,
                          fillcolor='orange', #'RoyalBlue',
                          opacity=0.35))

fig.show()

source