How can I select a value from a filename and write a different value to a structure?

Hello All,

Firstly, my apologies for not being able to give you some example code here - a large part of the problem I am having is that I am a total novice with Matlab/coding, and I'm not sure even of the correct commands that will help me resolve this, so despite reading many forum entries and documentation - I just cant get a handle on what I need to write to get this to work!

With a lot of help from a colleague (who is no longer available to offer guidance unfortunately), I have created a way to enter several data files (.txt) at a time, and for different values to be drawn down from the raw data and to be stored in a structure for later use.

Now, roughly speaking what I want to happen is that if the filename.txt has a particular value at a particular point in the filename, then a different value is assigned to the structure. This is because different values in the filename means that the raw data has a different classification - so in effect the filename is coded.

For example, 1_filename.txt would mean the data is "green" data, 2_filename.txt would mean the data is "amber" data and so on. Therefore, if a file is imported in that is prefixed with a "1", then a field in the structure (which is called "filestore") would indicate "green" under a column header that is called "dataclass". This would need to be repeated for all raw data entries relative to how many were imported (so, I think 'length' needs to feature here?) and and their respective prefix would then generate a different entry for each row in the "filestore" structure.

I really hope that makes sense and that some of you will be kind enough to help me with this. I am more then happy to try as many iterations as you advise until this works!

Kind regards,

10B.

Answer 1

[dpb]

This is simple enough to parse the filename; just need to know where it is and how it's stored. I tend to process sequences of files using dir to return the structure with the desired names by using appropriate wildcard in the call so I'll demonstrate that...

clrs={'green';'amber'; ...};  % the table in sequence of the coding
d=dir('*filename.txt'):  % get the files that match
for i=1:length(d)
  clr=clrs(sscanf(d(i).name,'%d'));  % lookup the color in the table based on position
  filestore(i).dataclass=clr;
  ...whatever you do with the data in the file here...
end

[10B]

Thank you very much DPB - this works perfectly!

Regards

10B.

[dpb]

And, of course, you can get rid of the intermediary...

for i=1:length(d)
  filestore(i).dataclass=clrs(sscanf(d(i).name,'%d'));
  ...