MATLAB: Search a text in dat file

cdfopentextscan

Hello,

I have many dat files. I do not want to put my matlab code at the same place as the directory that contains the .dat files. Therefore, I change the directory as follows:

cd('D:Documents\Related Directory')

Now, I am at the directory that I want. I can open the files one by one. I know how to automize this.

fid=fopen('data1.dat');

Now that I have opened my dat file, I want to search for a particular text. This can be possible by reading it line by line until the end and searching for that text. The dat file has both number and alphabet. If it doesn't find that text, it goes to the next dat file and continues to search. If it ever finds that keyword, it notifies.

Can you please help me with that?

Thank you,

Emre

Best Answer

fid = fopen('filename.dat');
res={};
while ~feof(fid) & 
  res{end+1} =fgetl(fid);
end
fclose(fid);
s=regexp(res,yourtext);
r=find(cellfun('isempty',s))

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MATLAB: Concatenate data using fgets

You are closing the file in the loop. close the file after the loop. I assume the below should work.

function read_datapattern(filename)
fid = fopen(filename,'rt');
if fid < 0
  error('error opening file %s\n\n',filename);
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pattern = fgets(fid);
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MATLAB: How to read in a very large DAT file from xPC Target when I keep running out of memory using READXPCFILE in xPC Target 4.2 (R2009b)

You can read in a very large DAT file from xPC Target in partitions by use of the FSEEK and FREAD commands in xPC Target 4.2 (R2009b).

To do this, you need to know

a)The header size in the DAT file

b)The number of signals and the type of signal (int8, double)

If you had a DAT file of 11 signals saved as type double, the following code illustrates how you may retrieve this information piece-wise. Depending on your specific computer setup, you may need to read in shorter (or longer) partitions of data and save it accordingly.

fclose('all')
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ftest=fread(fid,5000)
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headersize=512;
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l=88000;  %=11signals * 8 bytes * 1000 time steps
[a,count2]=fread(fid,l);
str1=readxpcfile([header;a]);
%At this point you may save your variables str1 and str2, etc. to a MAT
%file and clear your workspace to free up the memory. You may wish to
%relaunch MATLAB as well
save str1.mat str1
clear
fclose(fid)
fid=fopen('DATA1.DAT');
%seek to the place in the file where you left off last time.
fseek(fid, count1+count2,'bof')
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str2=readxpcfile([header;a]);
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clear
fclose(fid)
fid=fopen('DATA1.DAT');
%To confirm that the data lines up correctly, plot it
plot([str1.data;str2.data])

Best Answer

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MATLAB: How to read in a very large DAT file from xPC Target when I keep running out of memory using READXPCFILE in xPC Target 4.2 (R2009b)

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