Kevin Bartlett

@Qi--Thanks for the comment and especially for the test code. I'll see if I can replicate the error.

I can't really rate this higher than a 4, because I've only used it in a single instance. That said, it did what I needed.

I'd also like to suggest that the documentation could be improved. It took me ages to figure out how to use a regular expression with grep.m, when a single example would have made it clear. For others who might be having the same problem, here is what I did:

[fl,p] = grep('-R','-s','Z.a5 0[04]',dataFileName);

'Z.a5 0[04]' is a regular expression (see "help regexp") that causes grep to search the specified file for the string 'Z' followed by any single character, followed by " 0", followed by "0" OR "4". p.match contains the matching line.

Incidentally, an explanation of the output arguments fl and p might be helpful. fl appears to contain the filename of the file searched, but I don't quite see the point of this, as the argument p contains the same information in one of its fields.

Don't take my criticisms in the wrong way, though--this program is much-needed and much-appreciated!

@Qi--As near as I can tell, this is a bug with Java itself. I've added a description of the bug and the workaround to the program description above.

Thanks again for pointing this out.

Hi Kevin,

Your great script is exactly what I was looking for. However after playing with it for sometime, I found a problem. I use it to transmit a lot of data between two matlab processes. After a certain among of data has been transmitted, there will be an error happened as follow:

Error using jtcp>jtcp_write (line 373)
Java exception occurred:
java.lang.OutOfMemoryError: Java heap space

Error in jtcp (line 234)
jtcp_write(jTcpObj,mssg);

How much data can be transmited before the error happen depends on the java heap size setting in matlab. It seems the data was never cleared in the matlab java heap memory.

here is the code I use for testing:
%%%%%%%%%%%%%%%%%%%%%%%%
jTCPObj = jtcp('ACCEPT', 3000,'TIMEOUT',30*60*1000);
cnt = 0;
while 1
cnt = cnt + 1;

data = [];
while isempty(data)
data = jtcp('READ', jTCPObj);
end
disp(['data packet: ' num2str(cnt) ' received']);
end

%%%%%%%%%%%%%%%%%%%%%%%%
jTCPObj = jtcp('REQUEST','localhost',3000,'TIMEOUT',2000);
cnt = 0;
while 1
cnt = cnt + 1;
disp(['data packet: ' num2str(cnt)]);
data = rand(1024*1024, 1);
jtcp('WRITE', jTCPObj, data);
end

I am not familiar with java. I don't know it is I made some mistake or there is a problem related to java in your functions?

@jawad--If you type "help judp" at the Matlab command line, you should see three simple examples that ought to work as a starting point. The third example is simplest because it uses 'localhost' as the destination for the udp packet; this means you can run both the 'receive' and 'send' judp commands from the same computer (in separate Matlab sessions). Just make sure the specified port, 21566, is open in your firewall.