Using "unique" to identify unique values AND number of occurrences of each unique value
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Below is the head entries of a table
head(hits)
ID res1 score
_____________ ____ _______
AGAP001076-RD 282 0.67229
AGAP001076-RD 285 0.75292
AGAP001076-RD 286 0.66957
AGAP001076-RD 296 0.51694
AGAP001076-RD 298 0.51655
AGAP001076-RD 310 0.54564
AGAP001076-RD 314 0.74495
AGAP010077-RA 349 0.52136
Using "unique" I can obtain unique IDs. I would also like to obtain the number of occurences of each unique ID, e.g AGAP001076-RD 6
Thank you for your attention
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Accepted Answer
Steven Lord
on 19 Sep 2024
A = {'AGAP001076-RD' 282 0.67229
'AGAP001076-RD' 285 0.75292
'AGAP001076-RD' 286 0.66957
'AGAP001076-RD' 296 0.51694
'AGAP001076-RD' 298 0.51655
'AGAP001076-RD' 310 0.54564
'AGAP001076-RD' 314 0.74495
'AGAP010077-RA' 349 0.52136};
[counts, groupID] = groupcounts(A(:, 1))
3 Comments
Paul
on 19 Sep 2024
Check the linked doc page for groupcounts to see how to call it with a table input.
Steven Lord
on 19 Sep 2024
A = {'AGAP001076-RD' 282 0.67229
'AGAP001076-RD' 285 0.75292
'AGAP001076-RD' 286 0.66957
'AGAP001076-RD' 296 0.51694
'AGAP001076-RD' 298 0.51655
'AGAP001076-RD' 310 0.54564
'AGAP001076-RD' 314 0.74495
'AGAP010077-RA' 349 0.52136};
T = cell2table(A)
If your data is in a table array like the one I created above, you just have to tell groupcounts which variable(s) in the table is/are the grouping variable(s).
countsAndID = groupcounts(T, 'A1')
You can use multiple grouping variables as well. Let's make some data with duplicate rows and replace the values in A2 with ones more likely to cause a collision in the combination of the grouping variables A1 and A2.
T2 = T(randi(height(T), 20, 1), :);
T2.A2 = randi(5, 20, 1)
countsAndID = groupcounts(T2, ["A1", "A2"])
Let's check. How many rows of T2 have the same A1 and A2 values as the first row of the countsAndID table?
matchesForFirstRowA1 = matches(T2.A1, countsAndID{1, "A1"});
matchesForFirstRowA2 = T2.A2 == countsAndID{1, "A2"};
result = T2(matchesForFirstRowA1 & matchesForFirstRowA2, :)
Does that match the count that groupcount returned in that first row of countsAndID?
isequal(height(result), countsAndID{1, "GroupCount"})
More Answers (1)
Animesh
on 19 Sep 2024
In MATLAB, you can use the "unique" function along with the "histcounts" function to find the number of occurrences of each unique ID in your table. Here's how you can do it:
% Assume 'hits' is your table
% Extract the 'ID' column from the table
ids = hits.ID;
% Find unique IDs and their indices
[uniqueIDs, ~, idx] = unique(ids);
% Count the occurrences of each unique ID
occurrences = histcounts(idx, 1:max(idx)+1);
% Display the results
for i = 1:length(uniqueIDs)
fprintf('%s %d\n', uniqueIDs{i}, occurrences(i));
end
You can refer the following MathWorks documentation for more information on "histcounts" function:
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