Using for loop to enter data with similar names

I am trying to import data from 250 *.txt files. The file names are as such "C58501_line_ssf_001" to "C58501_line_ssf_250".

numfiles = 250;
filenames = 'C58501_line_ssf_%.txt'
results = cell(numfiles, 1);
for K = 1 : numfiles

   modpath = filenames{K};
   datastruct = load(modpath);
end

these files have multiple data rows for 55 individual paths. I want to import these *.txt files, extract the data from paths 16-20 and then get the individual values from 3 seperate columns. I am very uncertain on how to import all the data files and eliminate data down to the rows and columns I need.

Thank you in advance!

[jfrazie9]

The *.txt files are space delimited and have 1 header line

[Rik]

Have you taken a look at dlmread? It is not very often that using load for a file that is not a .mat immediately works as intended.

[jfrazie9]

filename = 'C58501_line_ssF_0001.txt'; delimiter = ' '; headerlines = 1; A = importdata(filename,delimiter,headerlines);

This code will load 1 of the files. That file comes out to be 1x1 struct with 2 fields.

[jfrazie9]

I have not looked at dlmread. How would I use that in a for loop to load all 250 files?

[Stephen23]

https://www.mathworks.com/help/matlab/import_export/process-a-sequence-of-files.html

[jfrazie9]

I began there from other questions asked and got something that created 1 7909x34 double when I need 250 7909x10 doubles using the following code

for k = 1:250

    textFilename = sprintf('C58501_line_ssF_%04d.txt',k);
    M = dlmread(textFilename,' ',1,0);
end

I would like to get these files in as 250 files as 7909x10 doubles and reduce them all to 7909x4 where the data form columns 1,2,3 and 6 are pulled out. After that I need to reduce it further so that all the values in column 1 with values of 16,17,18,19 and 20 are pulled out this should result in approximately a 500x4 double. I know what I am after I just have not been able to get an answer from looking at matlab tutorials and questions asked previously.

Any help is again greatly appreciated.

[Bob Thompson]

See comments on your other question.

For gathering multiple files you can also look at using the uigetfile() command. It only allows you to select from one directory at a time, but you are able to pick multiple files which it will index in a cell array of strings.

If the files are not able to be moved to a single directory then changing the string using sprintf and a for loop like you have is probably your best bet.

Answer 1

[Jan]

C = cell(1, 250);
for k = 1:250
  Filename = sprintf('C58501_line_ssF_%04d.txt',k);
  M        = dlmread(Filename,' ',1,0);
  C{k}     = M(ismember(M(:,1), 16:20), [1,2,3,6]);
end
Result = cat(1, C{:});