How to remove repeating elements from an array
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NS
el 25 de Sept. de 2011
Comentada: Life is Wonderful
el 12 de Abr. de 2020
Hi Guys,
I have two matrices X and Y of the same size. Each element in Y has a corresponding element in X. There are some repeating values in X (and correspondingly in Y as well). Is there any way to remove these elements from the matrices.
Thanks, NS
2 comentarios
Hesham Hendy
el 22 de Nov. de 2014
If I want to keep one value of repeated values without sorting, what can I do ???
Respuesta aceptada
UJJWAL
el 26 de Sept. de 2011
Hi NS,
Ok. Now I understand what you want. ok. There is a way to do this. Take a look at the code below :
a = randi(10,[1,20]);
[b,m1,n1] = unique(a,'first');
[c1,d1] =sort(m1);
b = b(d1);
In this way your problem is solved. similarly you can also do so for the other matrix. Hope this helps...
Happy to help
UJJWAL
2 comentarios
Andrei Bobrov
el 26 de Sept. de 2011
[a b] = unique([X;Y]','rows','first');
xyb = sortrows([a b],3)';
X = xyb(1,:);
Y = xyb(2,:);
Más respuestas (4)
UJJWAL
el 25 de Sept. de 2011
Use the unique function. Take the following example :-
a = randi(10,[1,20]) will display a 1 by 20 matrix of pseudorandom integers with uniform distribution in the range 1:10 . Obviously there will be repeated elements in the matrix. Suppose now you create a second matrix p = sin(a). So there is a mapping defined. Now type unique(a). It will give you only the unique values in a that is it will not display repeated values of the same element. Now type unique(p) : It will similarly display the unique values in p.
Hope it resolves your doubt
Best Wishes
Ujjwal
2 comentarios
Jan
el 25 de Sept. de 2011
If you want to remove elements on the same positions in both matrices, you can use the 2nd and 3th output of unique. See "help unique".
Fangjun Jiang
el 26 de Sept. de 2011
For duplicated x-y pairs, if you want to keep the last one:
X=[0 13 22 18 22 22 10];
Y=[0 1 3 -1 3 3 -1];
A=[X;Y]';
[UniXY,Index]=unique(A,'rows');
DupIndex=setdiff(1:size(A,1),Index);
A(DupIndex,:)=[];
X=A(:,1)'
Y=A(:,2)'
X =
0 13 18 22 10
Y =
0 1 -1 3 -1
If you want to keep the first one, use:
[UniXY,Index]=unique(A,'rows','first');
1 comentario
SIVAKUMAR KARURNKARAN
el 20 de Mayo de 2015
function B=adjacentmat(n,e) R=combntns(1:n,2); k=1:e; r=nchoosek(n,2); B=zeros(n,n,r,r);
for i=1:r for j=1:r R([i j],:)=R([j i],:); F=R(k,:); A=zeros(n,n); for m =1:e; A(F(m,1),F(m,2))=1; A(F(m,2),F(m,1))=1;
end
B(:,:,i,j)=A;
end
end
return in this output has more duplicate matrices i want only distinct matrices. i need the code of comparing the matrices and find which is distinct
0 comentarios
Ismet Ozturk
el 29 de Mzo. de 2018
Editada: Ismet Ozturk
el 29 de Mzo. de 2018
function [ a ] = deleteRepetation( a )
leng=size(a);tempa=zeros(1,2);
for i=1:leng(1)
tempa=a(i,:);
tempa=sort(tempa);
a(i,:)=tempa;
end
deletionList=[1];
while size(deletionList)>0
deletionList=[];leng=size(a);
for i=1:leng(1)
tempa=a(i,:);
for j=i+1:leng(1)
if tempa==a(j,:)
deletionList=[deletionList j];
end
end
end
a(deletionList,:)=[];
end
1 comentario
Life is Wonderful
el 12 de Abr. de 2020
Couple of things noted and suggestion added for the above code
Code point-1
tempa=sort(tempa);
Replace with
tempa=sortrows(tempa);
Code point-2
if tempa==a(j,:) %might NOT always work for Tables
Replace with
if isequal(tempa,a(j,:)) % better implementation
Ver también
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