connecting matlab and ros in same computer

edit

hi every one.I'm so begginer with ros and I want to run talker.m in matlab and visulize it's results in ros (in linux terminal).but I can't connect matlab to ros.I use ubuntu 16.04 and ros kinetic version.I set ros_ip=my_pc_name:11311 and my matlab ip as my pc ip using 'ifconfig'.In this code matlab gets this error: Error using talker (line 12) Cannot determine the message type of the /talker topic. Either the topic is not registered with the ROS master, or the ROS master is not reachable.

////////////////////////////////////matlab code

rosshutdown

ros_master_ip = 'http://localhost:11311';

matlab_ip = '192.168.42.10';

rosinit(ros_master_ip,'NodeHost',matlab_ip);

talker_sub = rossubscriber( '/talker' );

[chatter_pub, chatter_msg] = rospublisher('/chatter','std_msgs/String');

r = rosrate(2); % 2 Hz loop rate

pause(2) % wait a bit the roscore initialization