search and delete text lines when certain strings are missing
1 次查看(过去 30 天)
显示 更早的评论
Hi everyone, I have a text strings. This is just a little portion of the file but the original is much larger. Sometimes I get a row were something went wrong, like the third row of this example just below. On the third string part of the coordinates are missing, sometime part of the Northings, sometimes part of the Eastings, sometimes both. The rows that are right do not always have the same length. So I was thinking to look for those rows where either the 'N' letter or the 'E' letter are missing. I tried the 'strfind' and 'isempty' commands but I am not managing to get it right, it returns the same data as before. Can someone please help me??????? Thank you.
'$GPGLL,5341.65350044,N,00713.34866656,E,104325.00,A,D*64,$SDDBT,00023.2,f,0007.1,M,0003.8,F*08'
'$GPGLL,5341.65358961,N,00713.34455216,E,104327.00,A,D*6C,$SDDBT,00023,M,00.0,N,,K*4A'
'$GPGLL,5341.65523146A,D*68,$SDDBT,00023.2,f,0007.1,M,0003.8,F*08'
'$GPGLL,5341.65527973,N,00713.29472566,E,104351.00,A,D*69,$SDDBT,00023.2,f,0007.1,M,0003.8,F*08'
'$GPGLL,5341.65542543,N,00713.28847321,E,104354.00,A,D*6E,$SDDBT,00023.2,f,0007.1,M,0003.8,F*08'
'$GPGLL,5341.65550430,N,00713.28218422,E,104357.00,A,D*6F,$SDDBT,00022.9,f,0007.0,M,0003.8,F*03'
$GPGLL,5341.71916345,E,105127.00,A,D*6E,$SDDBT,00032.8,f,0010.0,M,0005.4,F*0F'
'$GPGLL,5341.65570054,N,00713.27593477,E,104400.00,A,D*65,$SDDBT,00022.9,f,0007.0,M,0003.8,F*03'
'$GPGLL,5341.65608654,N,00713.26774575,E,104404.00,A,D*62,$SDDBT,00022.9,f,0007.0,M,0003.8,F*03'
0 个评论
回答(2 个)
Cedric
2013-7-11
编辑:Cedric
2013-7-11
If there cannot be any N or E other than those for Northings and Eastings, you can proceed as follows:
fh = fopen('myData.txt', 'r') ;
while ~feof(fh)
line = fgetl(fh) ;
if isempty(strfind(line, 'N')) || isempty(strfind(line, 'E'))
continue ;
end
% Valid line, treat it (here, we just print it for the example).
fprintf('%s\n', line) ;
end
fclose(fh) ;
If N or E can appear elsewhere, and it seems to be the case as in line #2, one option could be to count commas, e.g.
fh = fopen('myData.txt', 'r') ;
while ~feof(fh)
line = fgetl(fh) ;
if sum(line == ',') < 14
continue
end
% Valid line, treat it.
fprintf('%s\n', line) ;
end
fclose(fh)
But how are you treating valid lines afterwards? If they can have various formats and you need pattern matching, REGEXP could be an optimal solution. If they have a rather fixed format, SSCANF/TEXTSCAN/etc will certainly work well.
0 个评论
Muthu Annamalai
2013-7-10
编辑:Muthu Annamalai
2013-7-10
My recommendation is to use regexp split at ',' and process the resulting cell-array.
0 个评论
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Characters and Strings 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!