CODEWITHSUNDEEP
pythonpandasmatplotlibviolin-plot
R. Cox
R. Cox

Reputation: 879

Violin plot of a list of arrays

I have some data in the format:

[array([[0, 1, 2]], dtype=int64), array([[1, 2, 3]], dtype=int64)]

My data can be generated using:

di_DFs = {}
groups = [1,2]
for grp in groups:
    di_DFs[grp] = pd.DataFrame({'A' : [grp-1],
                                'B' : [grp],
                                'C' : [grp+1]})
data = []
for k in di_DFs:
    data.append(di_DFs[k].iloc[[0]].values)

I can plot it:

for v in data:
    plt.scatter(range(len(v[0])),v[0])

enter image description here

I would like to get a violin plot with 3 vertical violins where my pairs of points are in the scatter plot please, to compare the distributions within my arrays. I tried:

for v in data:
    plt.violinplot(v)

But I got:

enter image description here

Upvotes: 1

Views: 863

Answers (2)

R. Cox
R. Cox

Reputation: 879

I needed to re-format my data:

df_Vi = pd.DataFrame({'Z' : data[0][0],
                      'Y' : data[1][0]}, index=range(len(data[0][0])))
    
plt.violinplot(df_Vi)

enter image description here

Or, a version that works with more data:


di_DFs = {}
groups = [1,2,0,7]
for grp in groups:
    di_DFs[grp] = pd.DataFrame({'A' : [grp-1],
                                'B' : [grp],
                                'C' : [grp+1]})
data = []
for k in di_DFs:
    data.append(di_DFs[k].iloc[[0]].values)

Indexes = range(len(groups))
    
df_Vi = pd.DataFrame()
    
for inD in Indexes:
    df_Po = pd.DataFrame({inD : data[inD][0]},
                          index=range(len(data[0][0])))
    
    df_Vi = pd.concat([df_Vi, df_Po], axis=1)

plt.violinplot(df_Vi)

enter image description here

Upvotes: 0

Nikhil K.
Nikhil K.

Reputation: 301

I believe you need something like this:

for v in data:
    plt.violinplot(v)

Plots this:

enter image description here

Since the example dataset has only a few points, you will not see much of distribution but more like flat dashes/points. But try with more data points and it will do the needed.

Upvotes: 1

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