Index in position 2 exceeds array bounds (must not exceed 1).

Hello, I'm trying to run this code (gauss elimination), but i get an error message :Index in position 1 exceeds array bounds (must not exceed 1). the error message comes from ''while tmp<=n && IS(tmp,1)~=0 '' . What does "Index in position 1 exceeds array bounds (must not exceed 1)" mean? and how to solve this?

Here is code :

function [RL,HI]=inputt(BM,BS,IS,FS)
if nargin<4, error("4 Inputs required"),end
n=length(BS);
RL(1,1)=BM;
for i=1:n
    HI(i,1) = BS(i,1)+BS(i,1);
    tmp = i+1;
    while tmp<=n && IS(tmp,1)~=0 
        RL(tmp,1) = HI(i,1)-IS(tmp,1);
        tmp=tmp+1;
    end
    if tmp<=n
        RL(tmp,1) = HI(i,1)-FS(tmp,1);
    end
    i = tmp;
end

Answer 1

[Karim]

The error is due to the way you are accesing the data, based on you picture the inputs are row vectors. IS is a 1x6 vector. However in the script, you are trying to acces the data as a column vector --> IS (tmp,1) which fails since the input is a row vector.

There are two solutions, either change the input into column vectors (as shown below) or change the indexing in the script i.e. --> IS(1,tmp)

BM = 560.5;
BS = [0.865 1.025 0 2.230 2.355 0]';
IS = [0 0 1.58 0 0 0]';
FS = [0 2.105 0 1.869 2.835 1.76]';

[RL,HI]=inputt(BM,BS,IS,FS)

RL = 6×1

560.5000 -0.3750 0.4700 -1.8690 1.6250 2.9500

HI = 6×1

1.7300 2.0500 0 4.4600 4.7100 0

function [RL,HI]=inputt(BM,BS,IS,FS)

if nargin < 4
    error("4 Inputs required");
end

n=length(BS);
RL(1,1)=BM;
for i=1:n
    HI(i,1) = BS(i,1)+BS(i,1);
    tmp = i+1;
    while tmp<=n && IS(tmp,1)~=0 
        RL(tmp,1) = HI(i,1)-IS(tmp,1);
        tmp=tmp+1;
    end
    if tmp<=n
        RL(tmp,1) = HI(i,1)-FS(tmp,1);
    end
    i = tmp;
end
end