How to convert a string of characters to numbers?

I have the following string obtained from a text file (the text file has a lot of info so I had to go and look for certain lines):
0 0 0 0 0.1 0 0 0 BlaBla
Another line might look like this
1 0.013 0.0156 -0.104 0.0376 0.0624 0.132 0.132 BlaBlaBla
By the way I'm reading the file everything is now a string of characters.
How can I convert that to a vector? Notice that the last column is a string of characters. The white spaces on the first line is different than on the second one too.
Any help is appreciated thanks.

 Accepted Answer

Matt Fig
Matt Fig on 28 Sep 2012
Edited: Matt Fig on 28 Sep 2012
str = '1 0.013 0.0156 -0.104 0.0376 0.0624 0.132 0.132 Bla';
T = regexp(str,'-*\d*\.*\d*','match');
V = cellfun(@str2double,T)

7 Comments

Matt Fig
Matt Fig on 28 Sep 2012
Edited: Matt Fig on 28 Sep 2012
carlos Uribe comments:
"Thanks Matt that works when I have just one string...
Now my problem is that I have a cell of those strings (cell).
T = regexp(cell,'-*\d*\.*\d*','match');
works fine and gives me a cell T with many cells
V = cellfun(@str2double,T)
gives me a problem because I cannot input a cell there...
Any workarounds for this?"
Yes, just do the same for each element of T.
str = {'1 0.013 0.0156 -0.104 0.0376 0.0624 0.132 0.132 Bla'};
str(2) = {'22 0 3 0 0.1 0 0 0 BlaBla'};
T = regexp(str,'-*\d*\.*\d*','match');
V = cellfun(@str2double,T,'Un',0);
V{1}
V{2}
I was just trying to figure out if there was kind of a "vectorized" way of doing it...given that right now I have 10^8 of those strings.
You mean more vectorized than I showed above? How could it be more vectorized than what I showed above, since there are no MATLAB loops?
V = str2double(T); % Without CELLFUN
My bad..didn't see that you added two new values to cellfun...thanks for your help
Jan, that returns nans here...

Sign in to comment.

More Answers (1)

str = '1 0.013 0.0156 -0.104 0.0376 0.0624 0.132 0.132 Bla';
V = sscanf(str, '%g', 6);

1 Comment

Or for cell str:
V = cellfun(@(x) sscanf(x, '%g'),str,'Un',0);
Very nice... no call to REGEXP.

Sign in to comment.

Categories

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!