Running Script using Timer

I am trying to use Timer function to run a script at pre-specified interval (30 seconds). However, most of the examples, including MATLAB help, is directed towards using callback functions. However, when I tried something similar to use the script to run using timer, I get an error message.

Specifically, I am using Bloomberg's data function to get real time data and would like to simply revoke that Bloomberg function every 30 seconds.

Any help would be sincerely appreciated. Please feel free to ask question, if I am not being clear.

Thank you,

Answer 1

[per isakson]

The trick is to use an anonymous function. Try

    >> my_timer_test
    2013-12-05 22:09:31
    2013-12-05 22:09:43
    2013-12-05 22:09:55
    2013-12-05 22:10:07

where

    %%my_timer_test
        tmr = timer                                 ...
            (   'Name'          , 'my_timer'        ...
            ,   'TimerFcn'      , @(x,y) my_script  ...
            ,   'BusyMode'      , 'drop'            ...
            ,   'ExecutionMode' , 'fixedDelay'      ...
            ,   'Period'        ,  12               ...
            ,   'StartDelay'    ,  1                ...
            ); 

    start( tmr )

and

    %%my_script
    disp( datestr( now, 31 ) )

are two script files

[KKR]

I tried your example. However, when I put my code in there, it gives me some errors:

here is what I have as my_script

tend = datenum(year(now),month(now),day(now),hour(now),minute(now),0);
tst = datenum(year(now),month(now),day(now),hour(now),minute(now)-20,0);
d = timeseries(c,'ESZ3 Index',{tst, tend},5,'Trade');

I get the following error: Attempt to add "tend" to a static workspace. See MATLAB Programming, Restrictions on Assigning to Variables for details.

Any idea?

Thank you very much for your help.

[per isakson]

Try to use the {}Code button. It makes it easier to read the code.

[per isakson]

It is obviously not a good idea to use a script in the value of the property, TimerFcn. See Variables in Nested and Anonymous Functions and note especially: "Calling a MATLAB script that creates a variable". The property name contains the letters Fcn for a reason.

Thus, convert your script to a function.

[Alfonso Nieto-Castanon]

I imagine you probably want to run your script on the base workspace (as if you run it on the Matlab command window), right?.

If that is the case, in the example above simply change the portion that reads:

 @(x,y)my_script

into:

 @(varargin)evalin('base','my_script');

Hope this helps

[KKR]

in conjunction with previous issue with Timer, I ran into one more problem, hope you will be able to help me out:

I wrote another piece of script and I tried using Timer function, but second time it iterates through it - it gives me the following error message:

Error while evaluating TimerFcn for timer 'my_timer'

Java exception occurred: com.bloomberglp.blpapi.InvalidConversionException: Cannot convert String to Enumeration

Do you have any idea what is going on here? I can post the full error message, if you think that might be helpful. I sincerely appreciate your help.

Kaushal

[per isakson]

Matlab is not always helpful! I guess the Blomberg page contained something else than digits in a field where "your" script expected digits.

See:

• Error messages like this one really frustrates me
• Debug code invoked by timer

[KKR]

Somehow it gives me an error - every time it goes to second iteration - first time invoke works perfectly fine.

[per isakson]

What does "it" refer to? Isn't it a case for ordinary debugging? http://undocumentedmatlab.com/ may have something useful to say on debugging Java code.

Answer 2

[KKR]

That worked.

Sorry about inconvenient code description.

Thank you very much for the help.