How do I find my wanted values in a .txt-file?

I succeeded to let Matlab read a .txt-file with two columns (let's say t and w) but now I want it to give me w(t), so for a certain value in the first column I want to know what the associated value is in the second column. Any ideas? I have been playing with ind=find(..) but couldn't make that work yet.

Answer 1

[Jacques]

Hi!

Have you tried readtable ?

http://www.mathworks.com/help/matlab/ref/readtable.html

[Evelyn]

Don't get it to work, but wouldn't the problem stay the same? If I have the table, how do I know what value in the second column belongs to the value I know to have in the first column?

[Matt Kindig]

I think ismember() might do the trick.

%create some sample data.
w= rand(10,1);  [~, t] = sort(w); 

%t values you want to match
tvals = [5; 3; 2];  
[~, loc] = ismember(tvals, t);  %where are tvals in t?
wvals = w(loc);  %corresponding w values

[Joseph Cheng]

if you have the txt file imported in (let's call it DATA which has size n by 2 where first column is t and the second column is the value for w associated with the t in the same row)then ind = find should work out fine. example:

DATA = [1:10]';
DATA = [DATA DATA.^2];
tindex = find(DATA(:,1) == 4); %find row with the desired value in first column
w = DATA(tindex,2) %get value to the right of the value you found for t.