Finding the lines where specific strings reside when reading a text file from Matlab

Question

I have a text file that has consequtive integer values around strings. This file looks like that:

This is the set for x = 100
---------------------------

For y=COLUMN 1 we have
1232
3ff3
4a45
23d4
5323
...
...
END of COLUMN 1 meas

For y=COLUMN 2 we have
1232
3c43
4545
2d24
5a23
...
...
END of COLUMN 2 meas

This is the set for x = 200
---------------------------

For y=COLUMN 1 we have
2b23
1232
d387
6f74
4c47
...
...
END of COLUMN 1 meas

For y=COLUMN 2 we have
354d
a546
3c63
5a46
a349
...
...
END of COLUMN 2 meas

This is the set for x = 530
---------------------------
..........
..........

What I would like to do is to strore the values in between the strings into seperate arrays. That is, from 'For y=COLUMN 1 we have' to 'END of COLUMN 1 meas' will be strored in to ArrayA, from 'For y=COLUMN 2 we have' to 'END of COLUMN 2 meas' into ArrayB, etc.

After that, I need to find all the values fo 'x' and store them into a string array named ArrayX. That is, this should be look like that:

ArrayX =

'x=100'    'x=200'    'x=501'

If anyone can help, I will really appreciate it.

Approximately how large is the total input file? If it will all fit into memory, then you may have some additional, relatively easy options using a series of regular expressions on the full character set. — Pursuit, Nov 19 '11 at 01:39
What exactly is your problem? You can read lines of a file using `fgetl` and extract information from them using regular expressions (see the `regexp` command). — Florian Brucker, Aug 28 '12 at 13:56

score 0 · Answer 1 · answered Oct 29 '15 at 14:28

I'm not sure you still need this information, but I have the same problem and find this solution for this;

formatSpec = 'This is the set for x = %s\n---------------------------\n\nFor y=COLUMN %s we have\n%s\n%s\n%s\n%s\n%s\nEND of COLUMN 1 meas\n\nFor y=COLUMN 2 we have\n%s\n%s\n%s\n%s\n%s\nEND of COLUMN 2 meas\n\n';
fileID = fopen('new.txt','r');
A = fscanf(fileID,formatSpec,[4 Inf]);
A=A';

Now I have big matrix with all needed symbols. I took your data and get this:

So the last step is to divide this matrix at several. For example for your ArrayX:

ArrayX = A(1:11:end,1:3)
ArrayX =

100
200
530

I can't find some elegant way to divide A at number of columns as you wanted and just done the same way using loop.

Finding the lines where specific strings reside when reading a text file from Matlab

1 Answers1