Improve use of structure in function

I have the following lines:

for x=1:800
    for y=1:500        
        [mystruct(y).I] = ...            
            insideFunc( ...
            mystruct(y).one(x),...
            mystruct(y).two.pwr(x),...
            mystruct(y).three.pwr(x),...
            mystruct(y).four,...
            mystruct(y).five,...
            mystruct(y).six...
            );
    end
end

It seems most of the time of the simulation is spent on those line. My guess is that getting the values from the structure (to feed the function insideFunc) consumes a lot of time (once it gets inside InsideFunc, it executes relatively fast ). My question is: is there way to improve the code by changing the way to collect the input data for the function?

[Mohammad Sami]

Can you perhaps unnest your structure.

mytable = struct2table(mystruct);

[Mohammad Sami]

Also do note that your code is overwriting the value for mystruct(y).I every time the value of x is incremented. Is this your intention ?

[Rub Ron]

Thanks. Actually struct2table rise much more the computation time. mystruct(y).I is overwritten I changed it and did not notice an improvement in the timing.

Answer 1

[Walter Roberson]

It might possibly be more efficient to use

for x=1:800
    for y=1:500
        sy = mystruct(y);
        [mystruct(y).I] = ...            
            insideFunc( ...
            sy.one(x),...
            sy.two.pwr(x),...
            sy.three.pwr(x),...
            sy.four,...
            sy.five,...
            sy.six...
            );
    end
end

In the special case where the vectors such as one() and two.pwr() are the same length for all entries, then there is potentially more acceleration available by using things like

my_ones = vertcat(mystruct.one);

After which

y_ones = my_ones(:,x);

for y = 1 : 500
    .... y_ones(y)
end

[Rub Ron]

Thanks for your answer. I implemented your first suggestion only, and it did not improve the timing (actually the time increase a little more). I wanted to add the second suggestion but, I get an error get I try to concatenate :

vertcat(mystruct.two.pwr)

Expected one output from a curly brace or dot indexing
expression, but there were 500 results.

this concatenation works fine:

vertcat(mystruct.one)

[Walter Roberson]

What is size(mystruct.two) and size(mystruct.two.pwr) ?

[Rub Ron]

mystruct.two is another structure, where pwr is one field. size of mystruct(1).two.pwr is 1x800 double