to speed up 'for' loop

Question

Michael Adelman 2012-8-1

0
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hello,

i have a loop with the following format:

for n = 1:length(x)
        if ....    
            .....
        elseif ....
            .......
        end    
    end

I suspect that it takes too long and my program is stuck. the length of 'x' currently 1200 cells and it might vary. How can I speed this up?

thanks,

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Rick Rosson 2012-8-2

Please post the actual and complete code...

Michael Adelman 2012-8-3

Hello Rick,

I'm sorry but I really can't post the actual code. The loop as I described is very simple and do check for the value of the cell and then do a substitution or addition to the current value.

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Answer 1

Walter Roberson 2012-8-1

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Processing 1200 items in an array would normally take too little time to measure meaningfully, unless the processing for each one takes a long time (in which case that is the problem rather than the for loop.)

I suggest you use the profiler to measure the performance. You could temporarily change the upper bound to something smaller than length(x)

You may wish to consider using waitbar()