Python call matlab function 'plot', The figure disappeared in few seconds.

When I use python call the matlab funtion plot, the figure only exists few seconds, then it colsed automatically. Why does have this phenomenon occur? How could I change or add something? Thank you very much.

AddTset.m

function c = AddTest(a,b)
   c = a + b;
   figure(1)
   plot(a,c,'DisplayName','test');
   %pause(30);
end

pyCallMat.py

import matlab.engine

if __name__ == '__main__':
    eng = matlab.engine.start_matlab()
    a = eng.AddTest(1.0,2.0) 
    print(a)
    b = eng.sqrt(4.) 
    eng.figure(3.0)
    eng.plot(a, b, nargout=0)

    print(b)

[Mohammad Sami]

I presume this maybe because the variable eng get cleared after your function is finished executing. this might perhaps close the matlab engine.

[Tianya Duan]

Hi，Sami, firstly thank you quick answer. I also think the eng may be the root cause, but do you know how to solve it?

[Tianya Duan]

The question has been solved by Chinese matlab support team.

Two methods:

1. add a line of the following command

input("Press Enter to continue...")

2. use the following answer of the website

isvalid function is more useful if you want to write a GUI.

while eng.isvalid(h):
    pass

[Villa Xue]

Thank you a lot, It works when use: input("Press Enter to continue...") in python