Demo functions

[Agrover112]

I had a few ideas regarding functions to add to the repository.
I'm not sure how this would break the CI/CD as it did in my commit which was just a fomatting.

• But I was thinking we should re-arrange the functions in the file according to their Shape?
• Also I encountered few function variants of the ones which are already implemented with noise?
  If required one could add them as well?

[Agrover112]

@guofei9987

[guofei9987]

Firstly thank you for your merge request!

It break the CI/CD because the code coverage rate decreased.
Just ignore the warning if you know what is going on.

New functions can also be added here https://github.com/guofei9987/scikit-opt/blob/master/examples/obj_func_demo.py

[Agrover112]

Why should we add in obj_func_demo? when another file called demo_func already exists? Any logical reasoning behind having two files?
I would suggest having a single file with all fns. Otherwise people using the api might get confused or find a missing import while importing from demo_func and obj_demo_func_demo .

[guofei9987]

When do pip install scikit-opt, all files in sko/ will be installed. So, There is no need to make the demo_func.py too big.

[Agrover112]

Ok no problem. I will add other if I find any in the examples.
Do you mind if I add more details to demo_func related to the func shape, type in docstring?
Also I need to add refs for the function in the Readme.