How should I make the system object variables global?

Hi all

I am writing a program in Matlab mfiles that has to run a third party software, CoppeliaSim. I write it in Object Oriented Programming in Matlab. I defined a class in a file and call the functions from the main file. the problem is the command

obj.client.step() 

Because I have to define it in the first functions VrepConnectorZMQ, but I need to call it again in the ApplyControl function to use it in every loop for each step. in this case , I get the error :

Dot indexing is not supported for variables of this type.

So what should I do? it looks like calling a method of a method is not possible in Matlab! Am I right?

How should I make the variable sim and client global?

classdef VrepConnectorZMQ


    properties
        sim;				%Similar to fd
        client;			%Used for server connection and server requests
        robot_joints = []	%List of joint handles
        		%Integration step used for simulation
        joint_pos=[];
    end

    methods


function obj = VrepConnectorZMQ()
            addpath("C:\Program Files\CoppeliaRobotics\CoppeliaSimEdu\programming\zmqRemoteApi\clients\matlab")
            javaaddpath('C:\Program Files\CoppeliaRobotics\CoppeliaSimEdu\programming\zmqRemoteApi\clients\matlab\jeromq.jar')

            client = RemoteAPIClient();
            client.setStepping(true);
            obj.sim = client.getObject('sim');			%RemoteAPI object
            obj.sim.startSimulation()
            obj.client.step();

            for i = 1:7 
                obj.robot_joints(i) = obj.sim.getObject(strcat('/LBR_iiwa_14_R820_joint',int2str(i)));
            end
            
            
        
            for i = 1:7
                obj.joint_pos(i) = obj.sim.getJointTargetPosition(obj.robot_joints(i));
            end
            
            % When simulation is not running, ZMQ message handling could be a bit
            % slow, since the idle loop runs at 8 Hz by default. So let's make
            % sure that the idle loop runs at full speed for this program:
%             defaultIdleFps = sim.getInt32Param(sim.intparam_idle_fps);
%             sim.setInt32Param(sim.intparam_idle_fps, 0);
        end



function ApplyControl(obj, u,steptime)
            
            
            startTime = obj.sim.getSimulationTime();
            t = startTime;
            while t<steptime
                for i = 1:7
                    obj.sim.setJointTargetVelocity(obj.robot_joints(i), u(i));
                    
                end
                t = obj.sim.getSimulationTime();

        
            end
            
        
        end

[Suvansh Arora]

In order to understand this better, I would need your help with the following information:

• How can I reproduce this issue at my end.
• Brief description of problem statement you are trying to solve.

[Farzad Torabi]

dear Suvansh

I doubt about reproducing, you need to have CoppeliaSim software too. EDU or paid version. but anyhow, I found the solution : I had to add obj before client to make it global. it resolved on matlab side. but I need to resolve the other part which is the integration and stepping. It looks like that when I use the function ApplyControl, I have to use the obj.client.step() repeatedly, but wherever I put it, the connection between Matlab and CoppeliaSim is lot after the first increment

obj.client = RemoteAPIClient();