execution order

2011 11 17
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What is the easiest way to control execution order of your code?
i have a function that creates an array of numbers and then I have a for loop that needs to use some numbers from that array. but the for loop seesms to be executing first.

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Jonathan
Jonathan 2011-11-17
Can you give us an example of this to clarify your question?
Baba
Baba 2011-11-17
time=function(pwd); % creates an array of numbers;
for i=1:10
...
...
need to use parts of time array here
end
but it seems that the time array gets populated after the for loop is executed.
Walter Roberson
Walter Roberson 2011-11-17
No, in such a situation, the "time" variable would get populated before the "for" loop starts.
However, please remember that "time" is the name of a MATLAB library routine, and functions cannot be named "function". When you use library routine names as variables, it is common to run in to unexpected effects.
Baba
Baba 2011-11-17
thank you!

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Jan
Jan 2011-11-17

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Matlab executes the code line by line in serial order. Inside a line the commands are executed from left to right.
Callbacks and timer functions are processed, if the command prompt is reached, or if PAUSE or DRAWNOW trigger their execution.
I do not see any possibilities to influence the order of execution.

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Baba
Baba 2011-11-17
thank you!
Walter Roberson
Walter Roberson 2011-11-17
In modern versions, timer callbacks can occur between any two lines, apparently.
Jan
Jan 2011-11-17
@Walter: Is this documented?
Walter Roberson
Walter Roberson 2011-11-17
No, not documented :(
http://www.mathworks.com/matlabcentral/answers/10394-timer-and-interruptible-off-button-callback-priority-preemption
Oh wait, here is official evidence!
http://www.mathworks.com/support/solutions/en/data/1-2QJ375/index.html?solution=1-2QJ375
And I think I might have traced back the discussion I was thinking of:
http://www.mathworks.com/matlabcentral/newsreader/view_thread/283728
Jonathan
Jonathan 2011-11-17
I would make a small modification to this answer. Inside a line, the commands are executed from left to right and inside to outside.
Daniel Shub
Daniel Shub 2011-11-17
@Walter, understanding timers is not that easy (and I am not sure you are implying it is easy). See my new question: http://www.mathworks.com/matlabcentral/answers/21537-what-thread-do-timers-operate-in
Jan
Jan 2011-11-17
@Jonathan: Exactly. Inside a line the precedence order rules, but for the same precedence the left operation is performed at first.

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