Matplotlib chart doesn't display in PyCharm

Which PyCharm version are you using? 

Could you please provide a code sample to reproduce the issue?

I use the last version of PyCharm Professional (2021.3.1).

Here is some code example:

%matplotlib inline
import random
import numpy as np
import matplotlib.pyplot as plt
import ipywidgets as widgets

_step = widgets.IntSlider(

min=1,
max=20,
step=1,
continuous_update=False,
description='Шаг:',
value=10,
orientation='horizontal',
readout=True
)

#Интерактивное управление параметрами модели с помощью виджетов
@widgets.interact(step = _step)
def plot(step=1):
    #размер окна
    plt.figure(figsize=(5, 5))
    plt.axis('equal')
    plt.grid(False)
    plt.axis((-2, 2, -2, 2))
    #изображаем множество точек, принадлежащих S1
    theta = np.linspace(0, 2*np.pi, 100)
    plt.plot(np.cos(theta), np.sin(theta), color='blue', linewidth=7)
    S = 2 #задаем масштаб по осям
    L=5 #длина изображаемого участка касательной и алгебры Ли

    for i in range(0, 360*2, step):
        th = i*np.pi/180/2 #угол в радианах
        #Значение матрицы поворота для заданного угла
        G = np.array([[np.cos(th), -np.sin(th)],[np.sin(th), np.cos(th)]])
        #Строим касательное пространство и алгебру Ли
        tangent_plane = np.column_stack((np.ones(100), np.linspace(-L, L,100)))
        tangent_plane = np.dot(G, tangent_plane.T).T
        plt.plot(tangent_plane[:,0], tangent_plane[:,1], color='orange')

Thank you,

There is a known issue with ipywidgets - https://youtrack.jetbrains.com/issue/DS-2766

Though the widget doesn't work, the graph is displayed correctly in my case, using your code sample:

If the issue is still relevant, could you please let me know your python version, and the output of `pip freeze` ?

I found that matplotlib needed to have a ENV variable set or this code
matplotlib.use('TkAgg')
to show the plot window on windows10 in pycharm.

@conradbraam that was a great hint for me as well, plots showing up in pop up windows.
But the strange thing was that one showed up in application (Plot tab) but the other did not. What was the difference?

plt.show()

was missing from the one that did not work without TkAgg!

Looking at your code above plt.show() is missing from both.