Natural-Order Row Sort

Alphanumeric row sort of a cell/string/categorical/table array, with customizable number format.

To sort any file-names or folder-names use NATSORTFILES:

http://www.mathworks.com/matlabcentral/fileexchange/47434-natural-order-filename-sort

To sort the elements of a string/cell array use NATSORT:

http://www.mathworks.com/matlabcentral/fileexchange/34464-customizable-natural-order-sort

Summary

Alphanumeric sort the rows of a string/cell/categorical/table array. Sorts the text by character code taking into account the values of any number substrings. Compare for example:

>> X = {'x2','10';'x10','0';'x1','0';'x2','2'};
>> sortrows(X) % Wrong numeric order
ans =
    'x1'     '0'
    'x10'    '0'
    'x2'     '10'
    'x2'     '2'
>> natsortrows(X) % Correct numeric order
ans =
    'x1'     '0'
    'x2'     '2'
    'x2'     '10'
    'x10'    '0'

By default NATSORTROWS interprets all consecutive digits as integer numbers, the number substring recognition can be specified using a regular expression: see NATSORT for details.

File Dependency

The natural-order sort is provided by the function NATSORT (File Exchange 34464). All of NATSORT's optional inputs are supported by NATSORTROWS.

Examples

>> A = {'B','2','X';'A','100','X';'B','10','X';'A','2','Y';'A','20','X'};
>> sortrows(A) % SORTROWS for comparison.
ans =
   'A'  '100'  'X'
   'A'    '2'  'Y'
   'A'   '20'  'X'
   'B'   '10'  'X'
   'B'    '2'  'X'
>> natsortrows(A)
ans =
   'A'    '2'  'Y'
   'A'   '20'  'X'
   'A'  '100'  'X'
   'B'    '2'  'X'
   'B'   '10'  'X'
>> natsortrows(A,[],'descend')
ans =
    'B'  '10'  'X'
    'B'   '2'  'X'
    'A' '100'  'X'
    'A'  '20'  'X'
    'A'   '2'  'Y'

>> sortrows(A,[2,-3]) % SORTROWS for comparison.
ans =
   'B'   '10'  'X'
   'A'  '100'  'X'
   'A'    '2'  'Y'
   'B'    '2'  'X'
   'A'   '20'  'X'
>> natsortrows(A,[],[2,-3])
ans =
   'A'    '2'  'Y'
   'B'    '2'  'X'
   'B'   '10'  'X'
   'A'   '20'  'X'
   'A'  '100'  'X'
>> natsortrows(A,[],[false,true,true],{'ascend','descend'})
ans =
   'A'    '2'  'Y'
   'B'    '2'  'X'
   'B'   '10'  'X'
   'A'   '20'  'X'
   'A'  '100'  'X'
>> natsortrows(A,[],{'ignore','ascend','descend'})
ans =
   'A'    '2'  'Y'
   'B'    '2'  'X'
   'B'   '10'  'X'
   'A'   '20'  'X'
   'A'  '100'  'X'

T = cell2table(A);
natsortrows(T,[], [2,-3]) % TABLE
ans = 
    A1      A2      A3 
    ___    _____    ___
    'A'    '2'      'Y'
    'B'    '2'      'X'
    'B'    '10'     'X'
    'A'    '20'     'X'
    'A'    '100'    'X'
natsortrows(T,[], {'A2','A3'},{'ascend','descend'}) % TABLE
ans = 
    A1      A2      A3 
    ___    _____    ___
    'A'    '2'      'Y'
    'B'    '2'      'X'
    'B'    '10'     'X'
    'A'    '20'     'X'
    'A'    '100'    'X'

>> B = {'ABCD';'3e45';'67.8';'+Inf';'-12';'+9';'NaN'};
>> sortrows(B) % SORTROWS for comparison.
ans =
   '+9'
   '+Inf'
   '-12'
   '3e45'
   '67.8'
   'ABCD'
   'NaN'
>> natsortrows(B,'[-+]?(NaN|Inf|\d+\.?\d*(E[-+]?\d+)?)')
ans =
   '-12'
   '+9'
   '67.8'
   '3e45'
   '+Inf'
   'NaN'
   'ABCD'

>> C = {'A2', 2; 'A10', 1; 'A2', 1}; % Scalar numerics in a column:
>> natsortrows(C,[],'sortnum')
ans =
    'A2'     [1]
    'A2'     [2]
    'A10'    [1]
>> natsortrows(C,[],'sortnum',{'ascend','descend'})
ans =
    'A2'     [2]
    'A2'     [1]
    'A10'    [1]