Sort according to specific string contained in file name

I have two lists of file names (including the whole path), at some point within the file name there is a subject ID and both lists contain exactly the same 25 IDs because there are two sets of files from each study participant. I need to sort the two lists so that the IDs correspond at each row, i.d. I want something like

List A List B

010822_AB030391 240922_AB030391

130922_FS120387 050322_FS120387

but right now what I have is

List A List B

010822_AB030391 050322_FS120387

130922_FS120387 240922_AB030391

because the lists are just sorted according to the first character and so the IDs don't correspond.

I had several ideas but they all seem too complicated or don't work well, e.g. I tried to split the file names at the underscore, to sort alphabetically and then merge the parts again. I also tried isolating the ID from one list, looping through that isolated list and finding the corresponding entry in the second list that contains a specific ID. But I think there should be a more elegant way to do this and I'd be happy to hear any tips! Right now both lists are character arrays, but maybe they should be a struct or something more easily manipulated.

[Dyuman Joshi]

The IDs are after the underscore ( _ ) ?

[TL]

Yes exactly, however there are some more underscores in the path before the file name, e.g.

'D:\DATA\XY\Project_XY\\label_sPR12345_AB67890-0011.nii '

The number of characters before the ID is always the same, also the number of delimiters before it

Answer 1

[Karim]

You can try spliting the lists, then ordering them and then using the indixes to sort the original list:

ListA = ["010822_AB030391";
         "130922_FS120387"];

ListB = ["050322_FS120387";
         "240922_AB030391"];            

% temporarly split the string to use the ID
tmpListA = split(ListA,"_");
tmpListB = split(ListB,"_");

% sort list A
[ListA_sort, orderA] = sort(tmpListA(:,2));

% find the corresponding order for list B
[~,orderB] = ismember(ListA_sort,tmpListB(:,2));

% order the original list
ListA = ListA(orderA)

ListA = 2×1 string array
    "010822_AB030391"
    "130922_FS120387"

ListB = ListB(orderB)

ListB = 2×1 string array
    "240922_AB030391"
    "050322_FS120387"

[TL]

That's (almost) perfect, thanks so much! The only problem is that there are several underscores before the ID and also some characters after the ID:

D:\DATA\XY\Project_XY\\label_sPR12345_AB67890-0011.nii '

and I can't figure out how to easily extract just the ID (e.g. "extract between the fourth underscore and minus"). I'm doing this in many steps now which is really cumbersome but I assume there is no other way

[Karim]

You can use the same idea/concept, but use it in a couple of steps. See below with some random data.

With the final list u can use the same procedure as in the answer.

MyFile = [ "D:\DATA\XY\Project_XY\\label_sPR12345_AB67890-0011.nii";
           "D:\DATA\XY\Project_XY\\label_sPR40922_AB03091-0011.nii";
           "D:\DATA\XY\Project_XY\\label_sPR30922_FS12038-0011.nii"];

tmpListA = split(MyFile,"\")

tmpListA = 3×6 string array
    "D:"    "DATA"    "XY"    "Project_XY"    ""    "label_sPR12345_AB67890-0011.nii"
    "D:"    "DATA"    "XY"    "Project_XY"    ""    "label_sPR40922_AB03091-0011.nii"
    "D:"    "DATA"    "XY"    "Project_XY"    ""    "label_sPR30922_FS12038-0011.nii"

% pick the last column of the first tmp list
tmpListA = split(tmpListA(:,end) ,"_")

tmpListA = 3×3 string array
    "label"    "sPR12345"    "AB67890-0011.nii"
    "label"    "sPR40922"    "AB03091-0011.nii"
    "label"    "sPR30922"    "FS12038-0011.nii"

% again pick the last column
tmpListA = split(tmpListA(:,end) ,"-")

tmpListA = 3×2 string array
    "AB67890"    "0011.nii"
    "AB03091"    "0011.nii"
    "FS12038"    "0011.nii"

% finaly only keep the first column
tmpListA = tmpListA(:,1)

tmpListA = 3×1 string array
    "AB67890"
    "AB03091"
    "FS12038"

[TL]

Works perfectly, thank you so much! This will be very useful long term, this issue keeps coming up in my project

Answer 2

[Stephen23]

S = ["D:\DATA\XY\Project_XY\label_sPR12345_AB67890-0011.nii";
     "D:\DATA\XY\Project_XY\label_sPR40922_AB03091-0011.nii";
     "D:\DATA\XY\Project_XY\label_sPR30922_FS12038-0011.nii"];
[~,X] = sort(regexp(S,'[A-Z]+\d+\-','match','once'));
S = S(X)

S = 3×1 string array
    "D:\DATA\XY\Project_XY\label_sPR40922_AB03091-0011.nii"
    "D:\DATA\XY\Project_XY\label_sPR12345_AB67890-0011.nii"
    "D:\DATA\XY\Project_XY\label_sPR30922_FS12038-0011.nii"