To eliminate the lines begin with "%"

Question

aneps 2013-11-25

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/107426-to-eliminate-the-lines-begin-with

回答： Image Analyst 2013-11-26

Testfile.txt

I have a file (attached here) which I need to eliminate all the lines begin with "%" and remove the "commas" after the numbers. Then read the numbers and put in separate columns X, Y and Z. Can anyone help me to make the program?

2 个评论
显示无隐藏无

Walter Roberson 2013-11-25

The file did not get attached.

aneps 2013-11-25

Thank you... Now the file is attached

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Simon 2013-11-25

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/107426-to-eliminate-the-lines-begin-with#answer_116235

在 MATLAB Online 中打开

Hi!

Read in your file:

% read in a file
fid = fopen(FileName);
FC = textscan(fid, '%s', 'delimiter', '\n');
fclose(fid);
FC = FC{1};

You can get rid of all "%" lines if you compare the first char like:

FC = FC(~strncmp('%', FC, 1));

You can get rid of all ',' with a regex like:

FC = regexprep(FC, ',', '');

Afterwards you can parse your cell array FC line-by-line with sscanf to extract numbers.

3 个评论
显示 1更早的评论隐藏 1更早的评论

aneps 2013-11-26

This seems not working! As the file is bigger, I have uploaded in "transfer big files.com"(https://www.transferbigfiles.com/dd8e3ef1-95c6-4fd8-a00e-908d2a0706d8/a8MGzUPeLZXl-HV0oJ-nMg2). The file name is VMIVolt.asc.

Here, when I run this program, the final data "A" is seems somehow messed up! I couldn't understand what has happened! If I manually delete all the lines in the data begin with "%" and compare with the one I got by running the program above doesn't seems to match. For example, all the elements in the third column in the original data are zeros but after running the above program, the zeros are replaced with some numbers! Thanks a lot.

Simon 2013-11-26

在 MATLAB Online 中打开

Hi!

It seems that sscanf fails for some reasons I don't know. But you can as well use

% use sscanf for each cell
A = cellfun(@(x) sscanf(x, '%f %f %f'), FC, 'UniformOutput', false);
% convert from cell array to numeric array
A = [A{:}].';

请先登录，再进行评论。