How can I fix "Index in position 2 exceeds array bounds" in for loop?

p=1;c=[1 0 4 8];n=4;b=[];j=1;

b=a(1,1)

a=flip(c)

for i=n-1:-1:1

b(1,i)=b(1,i+1)*p+a(1,i);

end

b

Answer 1

[Mathieu NOE]

hello

to make your code work, b should be initiallized with same dimensions as a (as a vector, not just one scalar)

also it's not clear when you write b=a(1,1) if you meant the first or last element (iteration) of vector b

p=1;
c=[1 0 4 8];
n=4;
j=1;
a=flip(c);
b=zeros(size(a));
b(1,4)=a(1,1);


for i=n-1:-1:1
    b(1,i)=b(1,i+1)*p+a(1,i);
end
b

b = 1x4

20 12 8 8

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[Mikhail]

Thank you

Answer 2

[Torsten]

When you set

b = a(1,1)

, a is undefined in your code from above.

Further, b is a scalar value, namely b = a(1,1). When you enter the for-loop, you want to compute b(1,3) as

b(1,3) = b(1,4)*p+a(1,3)

. But b(1,4) does not exist.

Maybe you want to set

b(1,4) = a(1,1)

instead of

b = a(1,1)

- I don't know.

[Mikhail]

It does not work.