reading only a portion of a text file
31 次查看(过去 30 天)
显示 更早的评论
I would like to read in a text file that contains a header and footer of information, where the number of rows of the header/footer, and number of rows to read can vary.
Here is an example of a row of data I would like to read from the text file.
All rows start with the ARR++ and are delineated with ':' I now I need i most likely need to use fopen / fprintf / fget1 / textscan but hoping someone can help set this up.
One other thing with the rows of data I would like to read in, there is date information like: 2013320133. I would ideally like to read only the first 5 digits of that date and separate the year and quarter into separate columns -- 20133 --> 2013 3
Here is a better example of the type of file I would like to read in. I am only interested in the ARR++ lines. I would be interested to have only the first 5 digits of 2013420134. Thanks a lot.
UNA:+.? ' UNB+UNC:140305:1444++' UNH+:2:1:E6' BGM+74' NA+Z02+' NAD+M+50' ND+MS+C2' STS+3+7' DM+242:20144:203' GI+AR3' GS+1:::-' ARR++Q:S:C:A:1N:2013420134:708:1234.323:A:N' ARR++Q:S:C:A:1N:2013420134:708:12234.323:A:N' ARR++Q:S:C:A:1N:2013420134:708:133234.323:A:N' ARR++Q:S:C:A:1N:2013420134:708:132234.323:A:N' ARR++Q:S:C:A:1N:2013420134:708:123334.323:A:N' ARR++Q:S:C:A:1N:2013420134:708:1232134.323:A:N' ARR++Q:S:C:A:1N:2013420134:708:123324.323:A:N' ARR++Q:S:C:A:1N:2013420134:708:123234.323:A:N' UNT+16+' UNZ+1+I3800'
5 个评论
Image Analyst
2014-4-5
In the past 6 hours, have you at least given fgetl() or textscan() a try ? Or do you really really need us to do it 100% for you?
采纳的回答
更多回答(2 个)
Image Analyst
2014-4-5
OK Jeff I did it for you. It just took a couple of minutes. I copied the data you gave to a test.dat file. Then I wrote code to read it in using fgetl() and search for lines that start with "ARR++Q:S:C:A:1N:" based on code I got in the help for fgetl. Then I extracted the 5 numerical characters from the string and converted it to a double number. Here is the code for you:
fid = fopen('test.dat');
tline = fgetl(fid);
k = 1; % Counter for lines that are valid.
while ischar(tline)
disp(tline)
colonLocation = strfind(tline, 'ARR++Q:S:C:A:1N:');
if ~isempty(colonLocation)
subString = tline(17:21);
output(k) = str2double(subString);
k = k + 1;
end
tline = fgetl(fid);
end
fclose(fid);
% Print output to command window:
output
Results in the command window:
output =
20134 20134 20134 20134 20134 20134 20134 20134
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Text Data Preparation 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!