How to circumvent this error: Subscript indices must either be real positive integers or logicals.

Assume I have such a vector data=[2 4 5 6 8 3 5 6 7 8 9 …]

I want to set this condition (in addition to other conditions combined with an or )for a function

If data(i)== mod(sum(data((i-12):(i-1))),28)

Obviously I will get for numbers, which indexes are smaller then 13 this error below, but I cannot ignore this numbers since they will have to undergo another condition.

Subscript indices must either be real positive integers or logicals.

Is there a way to circumvent this error? Thank you!

[KSSV]

data((i-12):(i-1)) as you are calling indices subtracted by 12, your i should start with > 12.

Answer 1

[Jan]

When i is smaller than 13, e.g. 12, the expression

data((i-12):(i-1))

becomes:

data(0:11)

but 0 is an invalid index. So either use

data(max(1, i-12):(i-1))

or decide, what should happen instead. The currently provided information does not allow to guess a replacement, which satisfies your needs.