I have to write this down twice?

X(i1:i2) = X(i1:i2) - const;

Do I have to use X(i1:i2) twice in the line to achieve the result above?

Answer 1

[Image Analyst]

Yes, that's correct.

Would you expect some other way to add a constant to just some of the elements in the vector? If so, what?

Answer 2

[Walter Roberson]

idx = i1:i2;
X(idx) = X(idx) - const;