How to save some values from one vector to another

I have 2 files and I saved them in one vector:

clc
clear all
D1=importdata('M1.txt');
t1=D1(:,1);  A1=D1(:,2);
D=importdata('M2.txt');
t=D(:,1);  A=D(:,2);
Af=[A1
A]; 

In this case Af will be a 1004 X 1 vector.

Now if I want to save all values between 0 and 0.05 in Af in another vector; how should I do that ?

I know I have to do it in a for loop but I failed. Can anyone help me ?

[Stephen23]

"In this case Af will be a 1004 X 1 vector. "

Given that each of the files contains 5002 rows, I suspect you mean that Af will have 10002 rows.

Answer 1

[Stephen23]

"I know I have to do it in a for loop but I failed."

Why do you need to use a loop? The MATLAB way is to use simple logical indexing:

Af  = [A1;A];
idx = Af>=0 & Af<=0.05;
new = Af(idx)

Basic MATLAB concepts, like how to use indexing, are introduced here:

https://www.mathworks.com/help/matlab/getting-started-with-matlab.html