find values between constants in vector

I have a vector freq_n where I want to find the indices corresponding to values between a and b.

freq_in-10*delta_f <= freq_n <= freq_in+10*delta_f

How would I go about doing this? The find() function seems to only allow one relational operator, unless I am doing something wrong? thanks!

Answer 1

[Sean de Wolski]

idx = X >= a & X <= b;

where X is your vector, a is the lower bound, b is the upper bound. This will be their logical values. If you want numerical indices:

find(idx)

Answer 2

[Wayne King]

freq = 0:1:500;
[~,indices] = find(freq>20 & freq < 250);
freq(indices)

Answer 3

[Leor Greenberger]

ah. I think I got it:

find(freq_n <= freq_in+10*delta_f & freq_n >= freq_in-10*delta_f)

I was initially using && and that wasn't working.