Need help filtering csv by values inside column
4 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Conor Nelson
le 8 Juil 2019
Commenté : Star Strider
le 12 Juil 2019
I have a large csv file(1034361x28). I want to look at column #1, and find rows containing the same column1 value and find the minimum value of column 2 for the new data set.
simple Ex.
if i have:
2 23
2 39
2 40
5 12
5 9
9 29
9 85
I need the code to find the minimum values for each subset of column 2(min of (23,39,40) and (12,9) and (29,85)).
How would i do so for a 1034361x28 file?
Thank You
0 commentaires
Réponse acceptée
Star Strider
le 8 Juil 2019
Try this:
A = [2 23
2 39
2 40
5 12
5 9
9 29
9 85];
[UA1,~,Ix] = unique(A(:,1));
Col2Max = accumarray(Ix, A(:,2), [], @min);
Out = [UA1, Col2Max];
producing:
Out =
2 23
5 9
9 29
6 commentaires
Star Strider
le 12 Juil 2019
Try this:
SameCol1 = accumarray(Ix, (1:size(A,1)), [], @(x){A(x,:)});
SameCol1{1}
producing:
ans =
2 23
2 39
2 40
And so for the others.
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur String Parsing dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!