extract from text file

Question

sas0701 2013-4-25

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/73559-extract-from-text-file

评论： D. Ali 2019-4-27

采纳的回答： Cedric

Hi, I am trying to use Matlab for this because I have ~300 files for which this needs to be done..

The data in the .txt file looks like this:

Event List

Patient Name: xyz Export Time: Thursday, April 11, 2013, 15:25:00 User Name: xyz Test ID: Name Time Duration Exam Start 00:00:00 00:00 Impedance - Impedance Values 00:00:00 00:00 Change - Montage Apply: 0bical.mtg 00:00:17 00:00 Calibration Off 00:00:18 00:00 Change - Montage Apply: 1doublebanana.mtg 00:00:36 00:00 . . .

I need a matrix file with 3 columns like this 00:00:00 00:00:00 Exam Start 00:00:00 00:00:00 Impedance - Impedance Values

i.e. 1) discard the first 7 lines.. 2) text goes into column 3 3) First values after text go into column 1 3) Second value + first value go into column 2

Is this possible?

Thanks, S

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Cedric 2013-4-25

You seem to be saying that your data is not available in column (i.e. it is a stream of characters) but then you say that the first 7 lines have to be discarded, which seems to indicate that there is some structure.

Reading

Patient Name: xyz Export Time: Thursday, April 11, 2013, 15:25:00 User Name: xyz Test ID: Name Time Duration Exam Start 00:00:00 00:00 Impedance - Impedance Values 00:00:00 00:00 Change - Montage Apply: 0bical.mtg 00:00:17 00:00 Calibration Off 00:00:18 00:00 Change - Montage Apply: 1doublebanana.mtg 00:00:36 00:00...

doesn't really allow me to determine what you call "text", or columns 1, 2, 3. Could you be more specific or reformat the question using "code" formatting?

There are several options for extracting data from a text file, ranging from TEXTREAD/SCAN, STRFIND, etc, for formatted enough content, to regular expressions for pattern matching in more complicated or less formatted content. Once you refine the question, we can talk about an appropriate approach.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Cedric 2013-4-25

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/73559-extract-from-text-file#answer_83496

编辑：Cedric 2013-4-25

在 MATLAB Online 中打开

New version, taking into account your last comment.

 fname_in   = 'myFile.txt' ;
 fname_out  = 'myFile.xlsx' ;
 headerSize = 8 ;
 fid = fopen(fname_in, 'r') ;
 % - Discard header.
 for k = 1 : headerSize
    if feof(fid)
      error('Structure discrepancy in %s', fname_in) ;
    end
    fgetl(fid) ;
 end
 % - Extract/process content.
 buffer  = cell(1e6, 3) ;                         % Cheap prealloc.. 
 lineCnt = 0 ;
 while ~feof(fid)
    lineCnt = lineCnt + 1 ;
    line = fgetl(fid) ;
    lStr = line(1:end-15) ;                       % Label string.
    dStr = line(end-13:end-6) ;                   % Date string.
    tStr= line(end-4:end) ;                       % Time string.
    fprintf('|%s|%s|%s|\n', dStr, tStr, lStr) ;   % Just for testing.
    buffer(lineCnt, :) = {dStr, tStr, lStr} ;
 end
 fclose(fid) ;
 buffer = buffer(1:lineCnt,:) ;                   % Truncate prealloc.
 % - Export to XLSX.
 xlswrite(fname_out, buffer) ;

You might want to improve the prealloc, adding blocks of cells when/if the initial size is too small. Note that this solution assumes the time stamp (date, time) to have always the same structure.

5 个评论
显示 3更早的评论隐藏 3更早的评论

Cedric 2013-4-26

编辑：Cedric 2013-4-26

在 MATLAB Online 中打开

If you look for "MATLAB Excel Mac" online, you'll see that managing Excel files on Macs has not been working until very recently. I think that your best option is to export to CSV if you want a format that can be read by Excel.

CSVREAD and DLMREAD won't manage text content though, so you can't use them to build the CSV file. One option is to implement the export in the loop that we just built (avoid at the same time the burden to build the cell array):

 fname_in   = 'myFile.txt' ;
 fname_out  = 'myFile_out.csv' ;
 headerSize = 8 ;
 fid_in  = fopen(fname_in, 'r') ;
 % - Discard header.
 for k = 1 : headerSize
    if feof(fid_in)
      error('Structure discrepancy in %s', fname_in) ;
    end
    fgetl(fid_in) ;
 end
 % - Extract/process content and output CSV content.
 fid_out = fopen(fname_out, 'w') ;
 while ~feof(fid_in)
    line = fgetl(fid_in) ;
    lStr = line(1:end-15) ;                       % Label string.
    dStr = line(end-13:end-6) ;                   % Date string.
    tStr= line(end-4:end) ;                       % Time string.
    fprintf('|%s|%s|%s|\n', dStr, tStr, lStr) ;   % Just for testing.
    fprintf(fid_out, '%s,%s,%s\n', dStr, tStr, lStr) ;
 end
 fclose(fid_in) ;
 fclose(fid_out) ;

sas0701 2013-4-26

Hi, I just tried the code on windows R2007b and got the same error. It looks like I am missing actxserver in both R2013(mac) and R2007b(windows). Not sure why but if I try

Warning: Could not start Excel server for export.

XLSWRITE will attempt to write file in CSV format.

> In xlswrite at 175

>> Excel = actxserver('Excel.Application');

Undefined function 'actxserver' for input arguments of type 'char'.

I'll start a new thread regarding this.. Thank you for you help on the above.. Very nice :)

请先登录，再进行评论。

Answer 2

sas0701 2013-4-25

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/73559-extract-from-text-file#answer_83488

编辑：sas0701 2013-4-25

Sorry here goes again - First line is Event List, there is an empty line between Event List and Patient Name also.So I basically want to ignore everything upto the 8th line - Exam Start..:

Event List

Patient Name:xyz

Export Time: Fri..

User Name: xyx

Test ID:

Name Time Duration

Exam Start 00:00:00 00:00

Impedance - Impedance Values 00:00:00 00:00

Change - Montage Apply: 0bical.mtg 00:00:23 00:00

Calibration Off 00:00:26 00:00

2 个评论
显示无隐藏无

Matt Kindig 2013-4-25

编辑：Matt Kindig 2013-4-25

Can you also post your intended output, i.e., what data after the 8th line that you want to retain, how you want to be structured, etc.? Your goal is still a bit unclear.

Cedric 2013-4-25

在 MATLAB Online 中打开

After the 8th line, you have multiple blocks of

 Exam Start 00:00:00 00:00
 Impedance - Impedance Values 00:00:00 00:00
 Change - Montage Apply: 0bical.mtg 00:00:23 00:00
 Calibration Off 00:00:26 00:00

that you want to transpose into a structure that has one row per block?

请先登录，再进行评论。