code is running too long, help me to optimize it

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Asliddin Komilov 2019-2-26

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编辑： Asliddin Komilov 2019-2-27

I have written a code, it runs slow. I don't know if it is because of the code or just it should take so long because of the number of loops and calculations.

can you help me to check/improve it please.

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madhan ravi 2019-2-26

upload your code

Asliddin Komilov 2019-2-26

PVTexergy_WT.m

here it is

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Answer 1

Jan 2019-2-26

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在 MATLAB Online 中打开

Start with inserting the code in a function, instead of using a script and try to use clear all to kill everything, which might be out of sight. This is a massive waste of time only.

Then mark the code with Ctrl-a and press Ctrl-i to apply a proper auto-indentation. This does not make the code faster, but much easier to debug. A lot of meaningful comments are essential also: Without it other readers cannot understand the purpose of the code- or you in some months. If I should work with this code, I'd give up immediately, because it is impossible to debug blocks like this:

        Tc(jj) = Tc(jj-1)+dTc(jj-1);
        Tt(jj)=Tt(jj-1)+dTt(jj-1);
        Twout(jj)=Twout(jj-1)+dTwout(jj-1);
        Tw(jj)=Tw(jj-1)+dTw(jj-1);
        Tg1(jj) = Tg1(jj-1)+dTg1(jj-1);
        Tadt(jj) = Tadt(jj-1)+dTadt(jj-1);
        Tadb(jj) = Tadb(jj-1)+dTadb(jj-1);
        t(jj)=t(jj-1)+1;
        Ub(jj)=Ub(jj-1);

For the actual problem use the profiler to find the bottleneck: Which line needs the most processing time? It is not worth to optimze some code, which takes a few percent of the total time only.

It is not called often in your code, but remember that 10.^-5 is an expensive power operation, while 1e-5 is a cheap constant.

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Asliddin Komilov 2019-2-27

编辑：Asliddin Komilov 2019-2-27

Thank you very much, I will make it function after I complete it. I used the profiler as you have suggested. The main problem is the Xsteam function and lines like Ex(Ex<0)=0, could you share some ideas on this?

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