MATLAB: Open Files by File Name Patterns

filter filesparsepatternsrecognize patterns

I am looking for the best Syntax to recognize patterns in file names and open the desired files/filter out unwanted files.

For example,

I have files named

HI_1C_TTTT4_468.xlsx
HI_2C_TTTT9_456.xlsx
HI_8C_TTTT7_279_Plot.xlsx
HI_5678_5487.xlsx

and I only wish to open the first two files, which have similar patterns unlike the last two. Any advice/examples?

Thank you!

Best Answer

regular expressions seem like the perfect candidate. In your case:

s = {'HI_1C_TTTT4_468.xlsx';
     'HI_2C_TTTT9_456.xlsx';
     'HI_8C_TTTT7_279_Plot.xlsx';
     'HI_5678_5487.xlsx'}
ismatch = ~cellfun(@isempty, regexp(s, '^HI_\dC_TTTT\d_\d{3}\.xlsx$', 'match', 'once'))

is one way to do it.

Related Solutions

MATLAB: Most efficient method to search through file names

I would create a function that parses the filenames and split them into variables of a table (or even a timetable). Then it's trivial to use matlab comparison functions to get the relevant rows of the table:

function filedetails = getdetails(filelist)
    %filelist: a structure array such as returned by dir
    filenames = vertcat(filelist.name); %convert the list of filename into a char array
    assert(size(filenames, 2) == 11, 'Length of file names not consistent with pattern')
    %temporary variables to create the table. Using string to make comparison easier
    Location = string(filenames(:, 1:3));
    Type = string(filenames(:, 4:7));
    Date = datetime(filenames(:, 8:11), 'InputFormat', 'MMyy');
    Filename = string({filelist.name}');
    %create the table
    filedetails = table(Location, Type, Date, Filename);
end

Now it's easy to filter the table according to whichever pattern you want:

filelist = dir('C:\somewhere\*.txt');  %whichever way you obtain your file list
filedetails = getdetails(filelist);
%Get all filenames matching Location XYZ
selectedfiles = filedetails.Filename(filedetails.Location == 'XYZ');
%Get all filenames matching Location XYZ or UVW
selectedfiles = filedetails.Filename(ismember(filedetails.Location, {'XYZ', 'UVW'});
%or
selectedfiles = filedetails.Filename(filedetails.Location == 'XYZ' | filedetails.Location == 'UVW');
%Get all filenames matching Type ABCD and location XYZ
selectedfiles = filedetails.Filename(filedetails.Type == 'ABCD' & filedetails.Location == 'XYZ');
%Get all filenames between January and March 2018
selectediles = filedetails.Filename(isbetween(filedetails.Date, datetime(2018, 1, 1), datetime(2018, 3, 31)));

Note the use of isbetween to get files between a date range.

MATLAB: Regexp to filter file names

s={'HI_A1C_TTTT4_468_07052016.xlsx'
  'HI_B2_TTTT9_Default452_070516.xlsx'
  'HI_GA1C_TTTT8_862_07052016.xlsx'
  'HI_HB2C_TTTT7_Default259_070516.xlsx'
  'HI_KA6_TTTT4_148_07052016.xlsx'
  'HI_B2C_TTTT9_Default1482_070516.xlsx'
  'HI_8C_TTTT7_279_Potato.xlsx'}
out=regexp(s,'\w+_\w+_\w+_(Default)?\d+_\d+','match','once')

Best Answer

Related Solutions

MATLAB: Most efficient method to search through file names

MATLAB: Regexp to filter file names

Related Question