How can I read Excel files, extract the rows which have top 10% values for a specific column and then write those rows in a new Excel file?

I have a folder that has multiple Excel files with names like xyz_1, xyz_2 and so on. I have to read each Excel file, extract the rows that have top 10% values for a column, and then write those rows into a new Excel file. I have been able to do the operation for 1 file. Now I am trying to do the operation for multiple files using a loop. But I am not sure how to go about that. For executing the operation for 1 Excel file, I did the following:

1. I read the Excel file and stored in a matrix.
2. I sorted the rows in descending order of values in one of the columns.
3. I read the first 10% of the rows.
4. I wrote a new Excel file with the rows obtained in #3.

Here is my code:

filename = fullfile(' _General Path_',' _Filename_.csv');
A = xlsread(filename,'A2:E31843');             %Read all cells if the file from A2 to E31843
B = sortrows(A,-5);                            % Sort the rows based on the descending order of column 5 values
C = B(1:3185,1:5);                             %Store the first 10% percent rows in a matrix
filename2 = fullfile(' _GeneralPath for new Excel files_',' _Filename_.xls');
xlswrite(filename2,C)                          %Write the first 10% rows to an Excel file

Can anyone please help me loop this above operation for multiple files (1090 files to be precise)?

Answer 1

[Image Analyst]

See the FAQ for code samples: https://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

Answer 2

[Nathan Jessurun]

Moving my comment into an answer:

Simply move your existing code into a function. In this case, you could do the following:

 function readSingleExcel(filename)
   % Your code here
 end

In another file (or an additional function in the same file, your choice), call that function:

 filenames = {'xyz_1.xls', 'xyz_2.xls'}; % This cell array holds your files
 for ii = 1:length(filenames)
   readSingleExcel(filenames{ii});
 end

If all files are in the same directory, you can make use of the 'dir' function:

 fileList = dir('./TopLevelDirectory/*.xls'); % Gets all directory info
 % We only want file names
 fileList = {fileList.name};