How do I sort an array according to the first column?
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Hi,
I have a cell array which I would like to sort according to the first column. But when I try using
high_emp_sort = sort(high_empathy_ID_factors);
% or
high_emp_sort = sortrows(high_empathy_ID_factors);
... then I only get back errors. Could somebody kindly help?
Jeff
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Accepted Answer
Image Analyst
on 28 Jul 2022
Edited: Image Analyst
on 28 Jul 2022
Did you mean by the first numerical column? Like this:
%====================================================================================
% Read in data.
storedStructure = load('high_empathy_ID_factors.mat');
ca = storedStructure.high_empathy_ID_factors;
data = cell2mat(ca(:, 2:end))
fprintf('Read %d rows by %d columns into data.\n', size(data, 1), size(data, 2));
%====================================================================================
% Sort by column 1.
fprintf('Sorting data by column 1.\n');
[sortedData, sortOrder] = sortrows(data, 1);
%====================================================================================
% Sort original cell array also.
fprintf('Sorting original cell array in the same order of rows.\n');
ca = ca(sortOrder, :)
Or did you really mean by the long alphanumeric hexadecimal strings in the first column? Like this:
%====================================================================================
% Read in data.
storedStructure = load('high_empathy_ID_factors.mat')
ca = storedStructure.high_empathy_ID_factors;
data = cell2mat(ca(:, 2:end))
[rows, columns] = size(data);
fprintf('Read %d rows by %d columns into data.\n', rows, columns);
%====================================================================================
% Convert hex numbers in column 1 to decimal
for row = 1 : rows
c = char(ca{row, 1});
% Can only convert the first 16 digits.
numbers(row) = hex2dec(c(1:16));
end
%====================================================================================
% Sort by column 1.
fprintf('Sorting data by column 1.\n');
[sortedData, sortOrder] = sort(numbers)
%====================================================================================
% Sort original cell array also.
fprintf('Sorting original cell array in the same order of rows.\n');
ca = ca(sortOrder, :)
3 Comments
Image Analyst
on 28 Jul 2022
Edited: Image Analyst
on 28 Jul 2022
See my edited answer above.
Or maybe read them into tables with readtable(), and use one of the members of the "join" functions to combine the tables.
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