has2k1 / has2k1/plotnine

position_dodge not working with categorical y and continous x variables

Open
#841 1 comment 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Orientation Aware Geoms
Dominant language
Python
Stars
4.8k
Forks
254
Avg merge
10h 35m
Merged PRs (30d)
9

Description

I illustrate the problem with the dots dataset:

import pandas as pd
from plotnine import *

dots = pd.read_csv('https://raw.githubusercontent.com/mwaskom/seaborn-data/master/dots.csv')

Now, I plot with categorical x and continuous y variable:

(
    ggplot(dots, aes(y='coherence', x='align', color='choice'))
    + geom_point(position = position_dodge(width=0.8))
)

image

This worked fine. Now, I swap the x- and y-axis:

(
    ggplot(dots, aes(x='coherence', y='align', color='choice'))
    + geom_point(position = position_dodge(width=0.8))
)

image
Now, position_dodge did not work anymore.

ggplot2 gives me what I would expect (I execute the following in a Jupyter notebook)

%load_ext rpy2.ipython
%%R -i dots
library(ggplot2)
(
    ggplot(dots, aes(x=coherence, y=align, color=choice))
    + geom_point(position = position_dodge(width=0.8))
)

image

Software versions:

import session_info
session_info.show()
-----
pandas              2.2.2
plotnine            0.13.6
session_info        1.0.0
-----

Click to view modules imported as dependencies

-----
IPython             8.26.0
jupyter_client      8.6.2
jupyter_core        5.7.2
-----
Python 3.12.4 | packaged by conda-forge | (main, Jun 17 2024, 10:23:07) [GCC 12.3.0]
Linux-3.10.0-1062.18.1.el7.x86_64-x86_64-with-glibc2.17
-----
Session information updated at 2024-07-15 16:29

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by running the two plotnine examples from the issue with the dots dataset, comparing position_dodge for categorical x versus categorical y. Trace the position_dodge and geom_point entry points to find why continuous x with categorical y is not separated, then add or update a regression test showing the expected dodged output.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
data-visualization
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
45/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.