Violin plot to plot in ascending order

📊 Plotly Python
1

Hi there,
I have created a violin plot but I would like the order of my plots to be in ascending numerical order. Before I plot the ‘data’ to my code I have sorted my data by the x values in the hope that this will help.
data = data.sort_values(by=[x_value])
However, the order of my data is still random and not in ascending order. Any advice on how to fix this issue would be greatly appreciated. I have attached a screenshot of how the plot currently looks like. I would just like to have the values on the x-axis in numerical order.

image
image1810×982 208 KB

2

The problem here is the [10.0-72.0) value, right? you’ll need to sort the strings using a “natural sort” rather than a string sort here basically.

3

Are you using Plotly Express here, like px.violin or are you building up your figure from graph_objects ?

4

Hi,
Thank you for your reply,
Im using plotly express here so px.violin. Yes that value is out of place. How would I sort the strings as ‘natural sort’? Do you mind providing me with an example?
Thank you!

5

Sure, here you go:

import plotly.express as px
import pandas as pd
import numpy as np
from natsort import natsorted

df = pd.DataFrame(dict(
    value = np.random.rand(30),
    bucket = ["[1-5)", "[10-15)", "[5-10)"]*10
))

px.violin(df, x="bucket", y="value", color="bucket",
         category_orders={"bucket": natsorted(df["bucket"].unique())})

image
image1922×782 47.9 KB

6

This is using the natsort module https://pypi.org/project/natsort/ which sorts strings “naturally” as opposed to strictly lexicographically, so that “10” appears between “1” and “20”.

7

Thank you for this! Worked perfectly.

8

With go.Violin it’s more complicated… you have to add the trace in the correct order, and you have to set xaxis.categoryarray I believe. This is the kind of thing that PX takes care of for you basically :slight_smile:

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