Index in position 2 exceeds array bounds (must not exceed 1). I want to plot "ev_s" versus "time i"

Hello, I have 10 EVs, and each EV have different battery capacity and load demand.

I want to sell the EV energy surplus to the other EV claster at time t interval, which is

t = 1:1:24; %hour
E =10;%EVs
ev_c = [26; 28; 24; 28; 24; 26; 28; 28; 26; 26];% EVs capacity
ev_L = [18; 19; 16; 19; 16; 18; 19; 19; 18; 18];% EVs EVs load demand
for i =1:t
    for j = 1:E
        ev_s(i,j) = ev_c(i,j)-ev_L(i,j);% EV surplus
    end
end
figure
plot(1:i,ev_s)% I want to plot ev_s versus time i

[Jem Jem]

any idea how could I fix it?

Thank you!!

[Torsten]

How do you want to plot an array with 10 elements (ev_s) against an array with 24 elements (t). Impossible.

Further ev_c and ev_L are vectors of size (10x1). But you try to access ev_c(i,j) and ev_L(i,j) for 1<= j <= 10. This will throw an error.

[Chandler Hall]

Instead of having ev_c and ev_L being constant arrays, you could implement them each as a function of two variables, time and EV# (1-10). Currently time plays no role at all.

[Jem Jem]

I had try to do the iteration loop using time interval (24 hours), but I don't get it...

Answer 1

[Walter Roberson]

t = 1:1:24; %hour

that is a row vector.

for i =1:t

t is a row vector, so that is equivalent to

for i = 1 : (1:1:24)

but when you use the : operator with non-scalars, only the first element of the non-scalar is selected. So that code is equivalent to

for i = 1 : 1

If you want to use i to loop over the indices of t, then you should be using

for i = 1 : numel(t)

After the loop, i will be left as the last value it was assigned, which (after the modification) would be 24

plot(1:i,ev_s)%

i is the last value that it was assigned by the for loop, so that is plot(1:24, ev_s) where ev_s is 24 x 10 . That is defined: plot() will automatically notice that the number of columns of ev_s does not match the number of elements of 1:24 but that the number of rows does match, so plot() will automatically treat that as-if you had plot(1:i, ev_s.') which would produce 10 lines with 24 points along each line.

... after the fix for the for i loop. Without the fix, you go into the plot as plot(1:1, ev_s) and that is a mismatch on the sizes.

[Jem Jem]

ccThanks for your explanation

I changed the first "for loop i" in to second step, used only "plot(ev_s)" and it seem work, but why the first step is not working as you mention it?, because the result what I got is till wrong.

t = 24; %hour

E =10;%EVs

ev_c = [26; 28; 24; 28; 24; 26; 28; 28; 26; 26];% EVs capacity

ev_L = [18; 19; 16; 19; 16; 18; 19; 19; 18; 18];% EVs EVs load demand

for j = 1:E%i = 1 : numel(t)

for i = 1 : numel(t)

ev_s(j,i) = ev_c(j,i)-ev_L(j,i);

end

end

figure

plot(ev_s)

[Torsten]

You have two 10x1 arrays (ev_c and ev_L). The array ev_s = ev_c - ev_L is also a 10x1 array.

Thus the only possible code with your data would be

ev_c = [26; 28; 24; 28; 24; 26; 28; 28; 26; 26];% EVs capacity
ev_L = [18; 19; 16; 19; 16; 18; 19; 19; 18; 18];% EVs EVs load demand
ev_s = ev_c-ev_L;
plot(1:10,ev_s)

[Jem Jem]

yes, I'm new for matlab, that is why I till facing errors

[Torsten]

The code above works as you can see from the plot.

If you want to do something else, please explain it.

[Jem Jem]

Yes, what I want to do is using time iteration loop, and then plot (time versus ev_s),

[Jem Jem]

Because the equation is (ve_s_j(i) equal to ev_c_j(i)-ev_L(i)).

%for j is equal to set of ev E %for i is equal to the time slot t

[Torsten]

In this case, you have to define ev_c as a matrix (e.g. 24x10), not as a vector (10x1).

[Jem Jem]

Thank you, this what I defined and updated, but for loop iteration is not working

clear all

clc

E =10;%EVs

t = 24; %hour

ev_c = zeros(E,t);

ev_L = zeros(E,t);

ev_c(:,t) = [26; 28; 24; 28; 24; 26; 28; 28; 26; 26];% EVs capacity

ev_L(:,t)= [18; 19; 16; 19; 16; 18; 19; 19; 18; 18];% EVs EVs load demand

for i = 1 : numel(t)

for j = 1:E %1 : 1:numel(t)

ev_s(j,i) = ev_c(j,i)-ev_L(j,i);

end

end

figure

plot(1:t,ev_s(1,:),'--*r','Linewidth',1);hold on

plot(1:t,ev_s(2,:),'--*b','Linewidth',1);hold on

plot(1:t,ev_s(3,:),'--*g','Linewidth',1);hold on

plot(1:t,ev_s(4,:),'--*k','Linewidth',1);hold on

plot(1:t,ev_s(5,:),'--*k','Linewidth',1);hold on

plot(1:t,ev_s(6,:),'--*k','Linewidth',1);hold on

plot(1:t,ev_s(7,:),'--*k','Linewidth',1);hold on

plot(1:t,ev_s(8,:),'--*k','Linewidth',1);hold on

plot(1:t,ev_s(9,:),'--*k','Linewidth',1);hold on

plot(1:t,ev_s(10,:),'--*k','Linewidth',1);hold on

grid on

hold off

[Torsten]

E = 10;%EVs
t = 24; %hour
ev_c = repmat([26; 28; 24; 28; 24; 26; 28; 28; 26; 26],1,t)% EVs capacity

ev_c = 10×24

26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 24 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26

ev_L = repmat([18; 19; 16; 19; 16; 18; 19; 19; 18; 18],1,t)% EVs EVs load demand

ev_L = 10×24

18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18

ev_s = ev_c-ev_L

ev_s = 10×24

8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8

plot(1:t,ev_s)
grid on