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pythonseabornvisualizationdata-analysisviolin-plot

Violin plot for positive values with python

I find violin plots very informative and useful, I use python library 'seaborn'. However, when applied to positive values, they nearly always show negative values at the lower end. I find this really misleading, especially when working with real-life datasets.

In the official documentation of seaborn https://seaborn.pydata.org/generated/seaborn.violinplot.html one can see examples with "total_bill" and "tip" which can not be negative. The violin plots show negative values, however. For example,

import seaborn as sns
sns.set(style="whitegrid")
tips = sns.load_dataset("tips")
ax = sns.violinplot(x="day", y="total_bill", hue="smoker",data=tips, palette="muted", split=True)

enter image description here

I do understand, that those negative values come from gaussian kernels. My question is, therefore: is there any way to solve this problem? Another library in python? Possibility to specify a different kernel?

Solution

  • You can use the keyword cut=0 to limit your plot to the data range. If the data doesn't have negative values, this will chop the end of the violin to zero. Using the same example as you, try:

    ax = sns.violinplot(x="day", y="total_bill", hue="smoker",data=tips, palette="muted", split=True,cut=0)