Script help: Import several .txt files into a single data matrix

Hi there,

I have limited knowledge on scripting but know that loops are very powerful tools that will save me days of time.

I currently require a script that can take a 300*1 (300 lines in one column) of text from a plain .txt file and can upload it into an array that has 168 columns, one for each file, forming a 300*168 array. The files must be in order (currently named #_meants.txt, but the numbers are not sequential) when uploaded. Could anyone point me in the right direction?

Many Thanks

Answer 1

[Michael Haderlein]

First, you need to get the file names:

files=dir('*_meants.txt');

If necessary, you order them by

[~,ind]=sort({files.name});
files=files(ind);

If possible, you can initialize your matrix:

values=zeros(300,length(files));

Then, you indeed need a loop going through the files:

for cnt=1:length(files)
   values(:,cnt)=dlmread(files(cnt).name);
end

Answer 2

[dpb]

d=dir('*.txt');
a=zeros(300,length(d));  % use given known size; if unknown read first outside loop 
for i=1:length(d)
  a(:,1)=importdata(d(i).name);
end

If the returned alphanumeric order isn't as needed, couple of choices --

a) sort the directory names as wanted, or

b) create a secondary file that has the list of names in desired order and traverse it instead of the directory.

http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

for more options but I'm terribly fond of the dir solution if at all possible--it's just so much cleaner...