Writing data to excel files, MATLAB

Question

I am using MatlabR2011a on my Windows 7 machine. I have a folder of 635 text files. Each file contains multiple rows and 2 columns. I am trying to loop through the folder and read each file and write these values to excel. So far this is what I have:

close all; clc;
  dirname = uigetdir;
  Files = dir(fullfile(dirname,'*.txt'))

  for k = 1:635
      j =1
      filename = fullfile(dirname,Files(k).name);
      fid = fopen(filename);
      x = fgetl(fid)
      while ischar(x)
          x = fgetl(fid)
          a2 = strtrim(x);
          a3 = textscan(a2,'%s');
          a4 = a3{1}{1};
          a5= a3{1}{2};
          pos3 = strcat('A',num2str(j));
          xlswrite('sample_output',{a4,a5},'Sheet1',pos3)
          j = j+1;
      end
         fclose(fid);
  end

It keeps giving me the following error after finishing reading the first file.

  Error using ==> strtrim Input should be a string or a cell array of strings.

A sample input file looks like this:

  15076 4636259
  15707 4636299
  15714 1781552
  15721 4204950
  15730 2174919
  16209 4636510
  16413 4758572
  16470 4445808
  17519 311397
  17667 2116489
  17739 1729694
  18024 3210756
  18627 3714194
  18695 4192858
  19141 632766
  19318 1923574
  19438 1255216
  19493 4635020
  19771 4770250

How can I fix this? Would appreciate help with this!

learnvst · Accepted Answer · 2012-03-23 00:30:15Z

1

In the while loop, cut the line

x=fgetl(fid)

...and paste it before the end statement right after j=j+1.

The error occurs because you get a line before the while statement, then you use the while statement to test validity of the string (all fine so far), but then immediately get the subsequent line before you perform your string operation. The call to fgetl at the start of the while block could return an EOF, causing subsequent string manipulation functions to fail.

Also... The code would be more robust if you set your for loop like so

for k=1:numel(Files)

edited Mar 23, 2012 at 0:30

answered Mar 22, 2012 at 23:55

learnvst

16.3k18 gold badges79 silver badges126 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

dawnoflife Over a year ago

Don't think it's being executed even once now. The excel file is blank. Probably because the x=fgetl command is so much later? Should I leave the first x=fgetl command in the same place aka before the while loop?

learnvst Over a year ago

Yes. Leave the first one in before the while loop. Move the second.

dawnoflife Over a year ago

I think the way I'm using the loops is wrong. It's overwriting the cells currently.

learnvst Over a year ago

My answer was only related to the error message that you reported in the question. Perhaps you need to initialize j before the first for loop for your new question

yuk · Accepted Answer · 2012-03-23 12:57:56Z

1

Since all your data are numeric this should work. Give it a try.

dirname = uigetdir;
Files = dir(fullfile(dirname,'*.txt'))
j =0;
for k = 1:numel(Files)
  filename = fullfile(dirname,Files(k).name);
  x = dlmread(filename,'\t'); %# I assume tab-delimiter
  j = j + size(x, 1);
  xlswrite( 'sample_output', x, 'Sheet1',sprintf('A%d',j) )
end

edited Mar 23, 2012 at 12:57

answered Mar 23, 2012 at 2:09

yuk

19.9k14 gold badges70 silver badges106 bronze badges

1 Comment

dawnoflife Over a year ago

It gives me DELIMITER must be a single character. error for the dlmread command.

Collectives™ on Stack Overflow

Writing data to excel files, MATLAB

2 Answers 2

4 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related