rossubscriber with callback missing messages

I'm using a rossubscriber to interface a C++ simulator with an algorithm written in Matlab. At each time step of the simulations I'm publishing a custom navigation message from ten different entities to one topic which I would like Matlab to parse for a separate navigation algorithm. Despite a very large buffer size or running the simulator very slowly, the ros subscriber will miss many of the messages from some entities while not missing others.

For example, in 23 messages from ten entities, my subscriber and call back recorded; 23, 14, 18, 15, 16, 18, 18, 19, 18, 23 messages. Is there something I'm missing to get the subscriber to read and parse all of the messages?

rosinit('XX.XX.XX.XX')
                                  
global Messages;
Messages = [];
global splineFits;
num_entitiez = 10;

splineFits = [];

for ii = 1:num_entitiez
    splineFit.ID = ii;
    splineFit.Time = [];
    splineFit.ECEF = [];
    splineFit.Vel = [];
    splineFit.Quat = [];
    splineFit.RotVel = [];
    
    splineFits = [splineFits; splineFit];
end


sub = rossubscriber('/Sim_State_msg','navigation_msgs/StateECEFWithCovariance',@navigationMessageReader,"BufferSize",1000000);


function navigationMessageReader(~,message,~)    
    global splineFits;
    global Messages;
    Messages = [Messages; message];
    Time = message.Header.Stamp.Sec + message.Header.Stamp.Nsec/1000000000;
    
    X = message.Pose.Pose.Position.X;
    Y = message.Pose.Pose.Position.Y;
    Z = message.Pose.Pose.Position.Z;
    
    vX = message.Twist.Twist.Linear.X;
    vY = message.Twist.Twist.Linear.Y;
    vZ = message.Twist.Twist.Linear.Z;
    
    qX = message.Pose.Pose.Orientation.X;
    qY = message.Pose.Pose.Orientation.Y;
    qZ = message.Pose.Pose.Orientation.Z;
    qW = message.Pose.Pose.Orientation.W;
    
    vR = message.Twist.Twist.Angular.X;
    vP = message.Twist.Twist.Angular.Y;
    vY = message.Twist.Twist.Angular.Z;
    ID = str2double(message.Header.FrameId);
    
    splineFits(ID).Time = [splineFits(ID).Time;Time];
    splineFits(ID).ECEF = [splineFits(ID).ECEF;X Y Z];
    splineFits(ID).Vel = [splineFits(ID).Vel;vX vY vZ];
    splineFits(ID).Quat = [splineFits(ID).Quat;qX qY qZ qW];
    splineFits(ID).RotVel = [splineFits(ID).RotVel;vR vP vY];
    
end

Answer 1

[Daniel Levy]

It looks like you wrote your subscriber right. It may be a problem with your publisher. Can you post the code of your C++ publisher?

[Daniel Levy]

Sure,

I create the publisher with

nh_ = std::make_shared<ros::NodeHandle>();
pose_scan_pub_ = nh_->advertise<navigation_msgs:StateECEFWithCovariance>("Sim_State_msg",1)
pub_ = advertise("LocalNetwork", "NoisyState");

and then publish I the message with

navigation_msgs:StateECEFWithCovariance ROSmsg;
pose_scan_pub_.publish(ROSmsg);

[Daniel Levy]

Try changing your advertise to

pose_scan_pub_ = nh_->advertise<navigation_msgs:StateECEFWithCovariance>("Sim_State_msg",100)

The second number is the queu size for your publisher and may be talking over itself.

[Daniel Levy]

Wow, that fixed it. I'm receiving all of my messages now, I feel like a real idiot not checking to see if my publisher queu size was long enough!

Thanks for the help Dan!