Make joyplot/ridgeline plot using dates as the x-axis

Question

I am plotting a joyplot where the x-axis is a range of dates. However, joyplot only accepts dates arguments as numbers... As a result, the chart is plotted correctly, but the x-axis displays dates as their serial number, which is not very friendly to the end user.

I have tried various methods to format the axis (like this one: Set x axis labels for joyplot), but none worked so far!

How can I format the x-axis so that it displays dates in the 'mm.yyyy' format (eg.: 01.2022)?

I am using the following database to plot this example (saved as a .csv to my computer): https://www.boxofficemojo.com/genre/sg4242469121/?ref_=bo_gs_table_24

Table example (copy it and paste in a .csv file, naming it "Example", as in code below):

Title	Release Date	Date	Distributor
Incredibles 2	Jun 15, 2018	43252	Walt Disney Studios Motion Pictures
The Lion King	Jul 19, 2019	43647	Walt Disney Studios Motion Pictures
Finding Dory	Jun 17, 2016	42522	Walt Disney Studios Motion Pictures
Frozen II	Nov 22, 2019	43770	Walt Disney Studios Motion Pictures
Shrek 2	May 19, 2004	38108	DreamWorks
Toy Story 4	Jun 21, 2019	43617	Walt Disney Studios Motion Pictures
Toy Story 3	Jun 18, 2010	40330	Walt Disney Studios Motion Pictures
Frozen	Nov 22, 2013	41579	Walt Disney Studios Motion Pictures
The Secret Life of Pets	Jul 8, 2016	42552	Universal Pictures
Despicable Me 2	Jul 3, 2013	41456	Universal Pictures
Inside Out	Jun 19, 2015	42156	Walt Disney Studios Motion Pictures
Zootopia	Mar 4, 2016	42430	Walt Disney Studios Motion Pictures
Finding Nemo	May 30, 2003	37742	Walt Disney Studios Motion Pictures
Minions	Jul 10, 2015	42186	Universal Pictures
Shrek the Third	May 18, 2007	39203	DreamWorks
The Lion King	Jun 15, 1994	34486	Walt Disney Studios Motion Pictures
Up	May 29, 2009	39934	Walt Disney Studios Motion Pictures
Minions: The Rise of Gru	Jul 1, 2022	44743	Universal Pictures
The Grinch	Nov 9, 2018	43405	Universal Pictures
Sing	Dec 21, 2016	42705	Universal Pictures
Monsters University	Jun 21, 2013	41426	Walt Disney Studios Motion Pictures

Code:

import joypy
import pandas as pd
import numpy as np
import matplotlib
import matplotlib.pyplot as plt

%matplotlib inline

df = pd.read_csv(r'C:\Users\Downloads\Example.csv', delimiter=';') #replace file name and directory with your file, created from the table above
print(df.shape)
df.head()

fig, ax = joypy.joyplot(df, 
                        by = 'Distributor', 
                        column='Date', 
                        colormap=cm.autumn, 
                        figsize = (10,6),
                        fade = True)

Output plot:

Answer 1

I managed to get the dates in the x-axis with help from the link you provided. I wanted to go through it in a bit of detail here.

Code for reading and formatting data

As joyplot only takes numbers, I converted the strings (Jan2, 2018 format) to dates and put them in Date column. Then to numbers using ordinal. I mention this because the numbers above are slightly different. It should not matter...

import joypy
import pandas as pd
import numpy as np
import matplotlib
import matplotlib.pyplot as plt

%matplotlib inline

df = pd.read_excel('example.xlsx') ## Copy pasted data into excel
df['Date'] = pd.to_datetime(df['Release Date'], format = '%b %d, %Y')
df['Date_Number'] = df['Date'].apply(lambda x:x.toordinal())

Create array to be used for axis

This is similar to what was in the other SO post. But, the data was from some time in 1991 to 2023. So, hardcoded them. Used 9 ticks as I thought that the 32 years would blend well having 8 interim labels. Also, used -12 so that just the year and month would show up. I think as all are Jan, you can remove that as well. Will leave it up to you...

# Generate date strings from a manually set start date
numdays = 9
start_date = "01-Jan-1991"
dates = pd.date_range(start = "01-Jan-1991", end ='01-Jan-2023',periods=numdays)
dates = [str(date)[:-12] for date in dates]

Plot graph and adjust the axis

As in the other post, used ax[-1] to get the last axis. But do note that I have used the set_ticks() to get the ticks, then the set_ticklables() for the labels and finally the xlim() to set the ends of the start and end points, like so...

fig, ax = joypy.joyplot(df,  by = 'Distributor', column='Date_Number', 
                        colormap=matplotlib.cm.autumn, figsize = (10,6), fade = True)

ax[-1].set_xticks(range(numdays))
ax[-1].set_xticklabels(dates)
ax[-1].set_xlim([0, 8])

...and the resulting plot is

Answer 2

First, please accept that the x-axis tick values in my answer may not be correct; it is unclear what the value obtained by ax[-1].get_xticks() indicates. Assuming it represents days, I can change it to a date in the following way: since the time series in maplotlib is Gregorian standard, I convert it from a number to a date.

df['Release Date'] = pd.to_datetime(df['Release Date'], format='%b %d, %Y')

import joypy
import pandas as pd
import numpy as np
import matplotlib
import matplotlib.pyplot as plt
from matplotlib import cm
import matplotlib.dates as mdates
%matplotlib inline

fig, ax = joypy.joyplot(df, 
                        by = 'Distributor', 
                        column='Date', 
                        colormap=cm.autumn, 
                        figsize = (10,6),
                        xrot=45,
                        fade = True)

print(ax[-1].get_xticks())
new_dates = [mdates.num2date(x +  mdates.date2num(np.datetime64('1900-01-01'))) for x in ax[-1].get_xticks()]
new_dates = [t.strftime('%b-%Y') for t in new_dates]
ax[-1].set_xticklabels(new_dates)

fig.show()