Calling octave .m function from python not executing

Question

I understand this question has been asked multiple times and answered in different forums but it looks like there are variants of the issue and mine is probably, slightly different.

Let me explain. I am trying to call a octave function which I had written for plotting and I don't want to re-write it again python. Therefore I did the following:- 1. install the oct2py 2. setup the OCTAVE_EXECUTABLE= c:\Octave\Octave-4.2.1\bin\octave-gui.exe 3. did the following in the code:-

  #importing oct2py 
  from oct2py import octave as oc

  oc.addpath("C:\\personal\\learning\\octave-lib") #containing my octave .m files

  #Now I am trying to call a plot function written in octave called displayData.m
  oc.displayData(X) # where X is a numpy matrix for plotting

However on executing call to the method gives no errors - but it does not do anything. I see a windows shell prompt opening & closing but nothing else.

I have also tried to replace octave-gui-4.2.1.exe with octave-cli-4.2.1.exe following the suggesting from some sites but I was getting errors that bulk of the windows dll required were not found. I started with the advice from the oct2py site asking me to just add the path to the folder containing octave.exe ( note that this folder contains all the octave executable) , but that resulted in windows permission errors. There should not be any reason for this error since I am the only user on my windows laptop and have administrative privileges. I am getting the following errors:-

  File "mcclassifier.py", line 21, in <module>
  from oct2py import octave as oc
  File "C:\Users\Sam\Anaconda3\lib\site-packages\oct2py\__init__.py", line 
 38, in <module>
 octave = Oct2Py()
 File "C:\Users\Sam\Anaconda3\lib\site-packages\oct2py\core.py", line 73, 
 in __init__self.restart()
  File "C:\Users\Sam\Anaconda3\lib\site-packages\oct2py\core.py", line 508, in restart     logger=self.logger)
File "C:\Users\Sam\Anaconda3\lib\site-packages\octave_kernel\kernel.py", 
line 144, in __init__
 self.repl = self._create_repl()
 File "C:\Users\Sam\Anaconda3\lib\site-packages\octave_kernel\kernel.py", 
 line 338, in _create_repl
 version = subprocess.check_output(version_cmd).decode('utf-8')
  File "C:\Users\Sam\Anaconda3\lib\subprocess.py", line 336, in check_output
**kwargs).stdout
  File "C:\Users\Sam\Anaconda3\lib\subprocess.py", line 403, in run
with Popen(*popenargs, **kwargs) as process:
 File "C:\Users\Sam\Anaconda3\lib\subprocess.py", line 707, in __init__
restore_signals, start_new_session)
File "C:\Users\Sam\Anaconda3\lib\subprocess.py", line 990, in 
_execute_child  startupinfo)
  PermissionError: [WinError 5] Access is denied

I tried to run it from Spyder IDE and also from the command line. Both have the identical behavior. Its been frustrating , so any suggestion to get me past this issue will be a big help !!

ADDITIONAL INFORMATION:- Probably I was not very clear above, but what I am trying to do is to execute a plotting function which i had implemented in octave, & is working.

I made some changes to my python code to see if I can instantiate the Oct2Py class and then call feval function. I commented the previous lines of code above and added the following:-

   octave=oct2py.Oct2Py()
   octave.feval('C:\\personal\\learning\\octave-lib\displayData',Xmat,timeout=80) 

I can see from the windows taskbar that octave-gui.exe being invoked and is seen as running in the background. But it is still not plotting and there is no error.

How do I make it run as foreground process and render the plot. What I want to do is similar to what is shown in the oct2py demo example at:- http://blink1073.github.io/oct2py/source/demo.html. As you can see that oc.plot([1,2,3],...) renders the plot. I will greatly appreciate any help here ?