How to read a term of the file

Hi, I would know if someone can help me with this. In the file I have, I only need to read the third term of the second column, I mean, the total_z colum, which in the first row is -9.471316e-01. So I need to obtain this term of all the file.

Thanks

[Bob Thompson]

I do not have the ability to look at your data. Would you describe the file layout as a numeric data sheet? If so, the simplest way to accomplish what you are asking for is to read the entire file into a matrix, and then extract that one value by indexing.

[Moises Belda]

I have something like that, which allows me to read the first term of this column, but I need to read the third term. I know I have to change something, but I quite confused with the %f and %s.

%%
ffs = 'h:\m\cssm\force.dat'; % change to your folder
fid = fopen( ffs, 'r' );
cac = textscan( fid, '%*f%s%*s%*s', inf, 'Headerlines',4, 'Delimiter','\t'); 
fclose( fid );
total_x = cellfun( @(chr) sscanf(chr,'(%f %*f %*f)'), cac{1} );

Answer 1

[infinity]

Hello,

Here is a solution that you can refer:

clear

format long

a = readtable('force1.dat','HeaderLines',4);

b = a(:,4);

c = b{:,1};

n = length(c);

d = zeros(n,1);

for i = 1:n

d(i) = str2double(c{i}(1:end-1));

end

d(1)

Your data is now saved in varibale d.

Best rergards,

Trung

[Moises Belda]

I have something like that, which allows me to read the first term of this column, but I need to read the third term. I know I have to change something, but I quite confused with the %f and %s.

%%

ffs = 'h:\m\cssm\force.dat'; % change to your folder

fid = fopen( ffs, 'r' );

cac = textscan( fid, '%*f%s%*s%*s', inf, 'Headerlines',4, 'Delimiter','\t');

fclose( fid );

total_x = cellfun( @(chr) sscanf(chr,'(%f %*f %*f)'), cac{1} );

[Bob Thompson]

%f and %s are Matlab flags that indicate the type of value you will be reading from the file. %f refers to a 'floating point number' which is a number with decimals, and %s refers to a string.

Did you write the code you provided, or did somebody else give it to you? Depending on how your data is stored in the file, it is likely that there are much more convenient ways of extracting the data. Trung has provided one such example.

[Moises Belda]

Yes, I read that in Matlab web, but I am not sure how to use them. Someone gave it to me, so if it is possible to read the third column like that would be fine. I upload the file in .zip, so you can download and read it

[Bob Thompson]

Have you tried Trung's answer?

[Moises Belda]

Not yet, until tomorrow I won’t check it.