Matplotlib：如何制作一个Numpy数组中的值的计数的堆积的图

Question

Hey I have the following problem. I have a array like this:

 arr1=
[[4 4 4]
 [4 4 6]
 [4 3 4]
 [4 4 7]
 [4 4 3]
 [4 4 1]
 [3 4 7]
 [4 3 7]
 [4 4 5]
 [4 3 6]]

Now i want to get a stacked bar plot(histogram), that shows the number of different elements,, like this:

My frist approach was to bincount the elements, fill the arrays up, but then i dont know what to do.

arr2=
    [[0 0 0]
     [0 0 1]
     [0 0 0]
     [1 3 1]
     [9 7 2]
     [0 0 1]
     [0 0 2]
     [0 0 3]]

Answer 1

Here is the output

and the code to generate the same

import numpy as np
import pandas as pd
data = np.array([[4, 4, 4],
 [4, 4, 6],
 [4, 3, 4],
 [4, 4, 7],
 [4, 4, 3],
 [4, 4, 1],
 [3, 4, 7],
 [4, 3, 7],
 [4, 4, 5],
 [4, 3, 6]])

columns = ['Col1', 'Col2', 'Col3']
df = pd.DataFrame(data, columns=columns)
out = {}
for column in columns:
    out[column] = pd.value_counts(df[column])

uniq_df = pd.DataFrame(out).fillna(0)

uniq_df.T.plot(kind="bar", stacked=True)

Answer 2

Adding an Altair based answer as well.

import numpy as np
import pandas as pd
from altair import *
data = np.array([[4, 4, 4],
 [4, 4, 6],
 [4, 3, 4],
 [4, 4, 7],
 [4, 4, 3],
 [4, 4, 1],
 [3, 4, 7],
 [4, 3, 7],
 [4, 4, 5],
 [4, 3, 6]])

columns = ['Col1', 'Col2', 'Col3']
df = pd.DataFrame(data, columns=columns)
df = df.T.stack().reset_index(level=[0,1])
df.columns = ['Col','RowNum','Value']
Chart(df).mark_bar().encode(y='count(*)', x='Col:N', color='Value:N')