execution order

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.

[Jonathan]

Can you give us an example of this to clarify your question?

[Baba]

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]

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]

thank you!

Answer 1

[Jan]

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.

[Baba]

thank you!

[Walter Roberson]

In modern versions, timer callbacks can occur between any two lines, apparently.

[Jan]

@Walter: Is this documented?

[Walter Roberson]

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]

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]

@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]

@Jonathan: Exactly. Inside a line the precedence order rules, but for the same precedence the left operation is performed at first.