How to take values from a data corresponding to specific value

I have a 400:2 txt. data. A value corresponding to 0.3 is 1.5373. How can I call the value of 1.5373 from the txt. data by putting 0.3 in the command board?

Please,anybody help me.

Answer 1

[KSSV]

Read about interp1. You can use interpolation and get it.

Also you can use logical indexing. But I prefer interp1. Let A be your 400*2 data.

x = A(:,1) ; y = A(:,2) ; 
% Using interp1
xi = 0.3 ; 
yi = intepr1(x,y,xi)
% using indices 
xi = 0.3 ;
idx = find(abs(x-xi)<10^-3);
yi = x(idx) ; 

[Murad Nuri]

yeah, worked perfectly. Thank you!