How to make functions run in parts of for loop

Hello world!

I'm making a script to calculate the energy balance of a small electricity grid with PV, ESS, EV etc. for all hours of 2016. In this script I want certain calculations and simulations to run for the summer months t = (2161:6552) and others for the winter months.

Is there a way to include functions for certain parts of the year?

Also, I want certain tasks (storing ESS) to be performed at certain hours during the 24h of a day, is it possbile to be this specific without calculating what hours of the 8760 this should occur?

Warm thanks!

Nils

[José-Luis]

How do your data look like?

[Nils Norlander]

I have load data and PV production for 8760 hours in column vectors. Max energy storage capacity of houses and batteries and charge/discharge power.

This is parts of the code.

for i = 1:5
  E_vp = E_vp+ P_vp_ch;
  E_load2(i) = E_load(i) + P_vp_ch;
end
for i = 6:9
  if E_load(i) > Allowed_winter
    E_load2(i) = E_load(i)-E_vp;
  end
end
for i = 10:15
  if E_pv(i) >= E_load(i)
    Ex_pv = E_pv(i)-E_load(i);
    E_load2(i) = 0;
    if E_bat < E_bat_max 
      if (0 < Ex_pv(i)) && (Ex_pv(i)) <= P_bat 
        E_bat = (min(E_bat + Ex_pv(i), P_bat));
        E_bat2(i) = E_bat;
        Ex_pv = Ex_pv-E_bat;
        Pv_out(i) = Ex_pv;
      elseif Ex_pv > P_bat
        E_bat = min(E_bat + ExcessPV, E_bat_max);
        Ex_pv(i) = Ex_pv(i)-E_bat;
        E_bat2(i) = E_bat; 
      end
    end
  elseif E_pv(i) < E_load(i)
    E_load2(i) = E_load(i)-E_pv(i);
    if E_bat < E_bat_max
      E_bat = min(E_bat+P_bat, E_bat_max);
      E_load2(i) = E_load2(i)+ Ebat;
    end
  end

[dpb]

If you'd store the data timestamps and use a table, you can likely do all without any loops or specific magic numbers at all...or at least cut it down to very few loops with only a couple of cases using logical addressing vectors for the two if...else...end branches.

ADDENDUM

Actually, given the description of "...have data and PV production for 8760 hours in column vectors", what are the magic numbers in the above loops of 1:5, 6:9, and 10:15 supposed to represent? They're surely not related to hours on further consideration as my initial reaction was as they don't cover the range at all.

Also the first loop has a very peculiar-looking expression of

    E_vp = E_vp+ P_vp_ch;

inside where the LH side isn't defined a priori yet is also in the expression RHS. Plus, it's all in the loop and there are no subscripts making it dependent upon the loop index at all. It likely isn't doing what's intended one would guess.

Answer 1

[D. Plotnick]

I don't know if there is a way to avoid having a bunch of if, elseif, else statements, although the idea of logical indexing is not a bad way of going (loops are something to avoid where possible). But, for simplifying the way you code, the below example should serve you well. You can write your code as a function and terminate the main function with an end (important). You can then write your special case functions below, again making sure to terminate them with an end statement. You can then call those cases from within the loop without as much code splatter. When you want a new case, just add its function below, and then use the appropriate if conditions to call it.

Note, you can also write functions that are called from within the case-functions.

 function out = rootFun(in)
 out = zeros(15,1);
 for ii = 1:15
     time = 24*rand(1); % lets just make up a random time
     if ii < 5
         out(ii) = summer(in(ii),time);
     elseif ii>=5 && ii<10
         out(ii) = winter(in(ii),time);
     else
         out(ii) = default(in,time);
     end
 end
 end

 function out = summer(in,time)
 out = 2*in;
 if time<12
     out = timefun(out);
 end
 end

 function out = winter(in,time)
 out = sqrt(in);
 if time > 8 && time <= 16.5
     out = timefun(out);
 end
 end

 function out = default(in,~)
 out = in;
 end

 function out = timefun(in)
 out = -in;
 end