Index exceeds matrix dimensions.

function [L]=LineData
% ---------------------------------data input------------------------------

%{
Transmission line parameters:

1st & 2nd column for line "From-To"
From | To | R | X | Bsh
%}
L =[1 2 0.1 0.2 0.02
    1 4 0.05 0.2 0.02
    1 5 0.08 0.3 0.03
    2 3 0.05 0.25 0.03
    2 4 0.05 0.1 0.01
    2 5 0.1 0.3 0.02
    2 6 0.07 0.2 0.025
    3 5 0.12 0.26 0.025
    3 6 0.02 0.1 0.01
    4 5 0.2 0.4 0.04
    5 6 0.1 0.3 0.03]
end
function [B]=BusData
% ---------------------------------data input------------------------------
%bus number| Bus type | voltage schedule | Pgen | Pload | Qload
syms Swing
syms Gen
syms Load
syms Pg
syms Pl
syms Ql
B =[1 Swing 1.05 Pg Pl Ql 
    2 Gen 1.05 0.5 0 0
    3 Gen 1.07 0.6 0 0
    4 Load 0 0 0.7 0.7
    5 Load 0 0 0.7 0.7
    6 Load 0 0 0.7 0.7]
end

%%different file

L=LineData;

%Load BusData input Here:
B=BusData;
%Transmission line parameters:
ln = L(:,1);
rn = L(:,2);
R = L(:,3);
X  = L(:,4);
%Bc = L(:,5);
%Bus parameters:
bn = B(:,1);
bt = B(:,2);
vs = B(:,3);
Pgen  = B(:,4);
Pload = B(:,5);
Qload = B(:,6);

%Number of Buses:
Nb = max(max(ln), max(rn));

mat= [
1.4286    5.0000         0    5.0000    3.3333         0
    5.0000    0.9524    4.0000   10.0000    3.3333    5.0000
         0    4.0000    1.6393         0    3.8462   10.0000
    5.0000   10.0000         0    1.4286    2.5000         0
    3.3333    3.3333    3.8462    2.5000    0.6410    3.3333
         0    5.0000   10.0000         0    3.3333    1.6667]

Bs=inv(mat)
syms Swing
syms Gen
syms Load
syms Pg
n = find(ismember(bt, Swing));
    Bs(n,:) = []
    Bs(:,n) = []
v = find(ismember(bt, Gen));
f = find(ismember(bt, Load));
P = zeros(Nb,1)
P= -Pload + Pgen
P(n,:)=[]
Q=Bs*P
sum(P)==Pg   
for i = ln , j = rn
    Pt(i,j)=(Q(i)-Q(j))/X(i,j);      %Transmission power
end

first can i make this code simple and short?

second why am i getting this error?did i miss something?

and Q depends on Busdata so if first or second or...bt=swing Q of that row is zero

[arian hoseini]

Index exceeds matrix dimensions.

Error in sym/subsref (line 814)

R_tilde = builtin('subsref',L_tilde,Idx);

Error in DCPowerFlow (line 64)

Pt(i,j)=(Q(i)-Q(j))/X(i,j); %Transmission power

Answer 1

[Walter Roberson]

You have

for i = ln , j = rn

Pt(i,j)=(Q(i)-Q(j))/X(i,j); %Transmission power

end

That is not a double-nested loop. That is instead equivalent to

for i = ln

j = rn

Pt(i,j)=(Q(i)-Q(j))/X(i,j); %Transmission power

end

which iterates over i but within each iteration of i it overwrites all of j with the vector rn .

format long g
L=LineData;

L

L = 11×5

1 2 0.1 0.2 0.02 1 4 0.05 0.2 0.02 1 5 0.08 0.3 0.03 2 3 0.05 0.25 0.03 2 4 0.05 0.1 0.01 2 5 0.1 0.3 0.02 2 6 0.07 0.2 0.025 3 5 0.12 0.26 0.025 3 6 0.02 0.1 0.01 4 5 0.2 0.4 0.04

%Load BusData input Here:
B=BusData;
%Transmission line parameters:
ln = L(:,1);
rn = L(:,2);
R = L(:,3);
X  = L(:,4);
%Bc = L(:,5);
%Bus parameters:
bn = B(:,1);
bt = B(:,2);
vs = B(:,3);
Pgen  = B(:,4);
Pload = B(:,5);
Qload = B(:,6);

%Number of Buses:
Nb = max(max(ln), max(rn));

mat= [
1.4286    5.0000         0    5.0000    3.3333         0
    5.0000    0.9524    4.0000   10.0000    3.3333    5.0000
         0    4.0000    1.6393         0    3.8462   10.0000
    5.0000   10.0000         0    1.4286    2.5000         0
    3.3333    3.3333    3.8462    2.5000    0.6410    3.3333
         0    5.0000   10.0000         0    3.3333    1.6667];

Bs=inv(mat);
syms Swing
syms Gen
syms Load
syms Pg
n = find(ismember(bt, Swing));
    Bs(n,:) = [];
    Bs(:,n) = [];
v = find(ismember(bt, Gen));
f = find(ismember(bt, Load));
P = zeros(Nb,1)

P = 6×1

0 0 0 0 0 0

P= -Pload + Pgen

P = 

P(n,:)=[]

P = 

Q=Bs*P

Q = 

sum(P)==Pg   

ans = 

for i = ln , j = rn
    Pt(i,j)=(Q(i)-Q(j))/X(i,j);      %Transmission power
end

j = 11×1

2 4 5 3 4 5 6 5 6 5

Index exceeds the number of array elements. Index must not exceed 5.

Error in sym/subsref (line 997)
R_tilde = builtin('subsref',L_tilde,Idx);

function [L]=LineData
% ---------------------------------data input------------------------------

%{
Transmission line parameters:

1st & 2nd column for line "From-To"
From | To | R | X | Bsh
%}
L =[1 2 0.1 0.2 0.02
    1 4 0.05 0.2 0.02
    1 5 0.08 0.3 0.03
    2 3 0.05 0.25 0.03
    2 4 0.05 0.1 0.01
    2 5 0.1 0.3 0.02
    2 6 0.07 0.2 0.025
    3 5 0.12 0.26 0.025
    3 6 0.02 0.1 0.01
    4 5 0.2 0.4 0.04
    5 6 0.1 0.3 0.03];
end
function [B]=BusData
% ---------------------------------data input------------------------------
%bus number| Bus type | voltage schedule | Pgen | Pload | Qload
syms Swing
syms Gen
syms Load
syms Pg
syms Pl
syms Ql
B =[1 Swing 1.05 Pg Pl Ql 
    2 Gen 1.05 0.5 0 0
    3 Gen 1.07 0.6 0 0
    4 Load 0 0 0.7 0.7
    5 Load 0 0 0.7 0.7
    6 Load 0 0 0.7 0.7];
end

[arian hoseini]

thank u so the problem is that Index exceed 5.so the Q has 5 values but it should be 6...so Q depends on Busdata so if first or second or...bt=swing Q of that row is zero ..(as i said it in the first time..looks like u missed it)

for example here Q = -2701139479547903547/11529215046068469760

-2345688154072473701/23058430092136939520

-7373970668296261/72057594037927936

80609037767370081/180143985094819840

-2468031588874529/1441151880758558720

from BusData the first row is Swing so i wanna add 0 to the up matrix

Q = [0

-2701139479547903547/11529215046068469760

-2345688154072473701/23058430092136939520

-7373970668296261/72057594037927936

80609037767370081/180143985094819840

-2468031588874529/1441151880758558720]

and i wrote P= -Pload + Pgen but i want to combine them instead of P= -Pload + Pgen

i tried P= [-Pload,Pgen] but i want it to be like this P=[

Pg orPl

1/2

3/5

-7/10

-7/10

-7/10]

[Walter Roberson]

Your values in column 1 and column 2 of your line data are absolute node numbers. You try to use them as indices. However, remember that you deleted data from your matrix, so any absolute index that was greater than the row or column that was deleted, needs to be reduced by the number of entries deleted.

maxnodes = max([ln; rn]);
forward_map = 1:maxnodes;

forward_map(n) = [];   %delete any entries corresponding to deleted nodes

BM = nan(1, maxnodes);
BM(forward_map) = 1:length(forward_map));
for i = BM(ln)
   for j = BM(rn)
        Pt(i,j)=(Q(i)-Q(j))/X(i,j);      %Transmission power
   end
end

or something like that.