Integrating Indices

2011 2 21
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Hello,
I have taken the matrix below and sorted it ascending by row:
(Original) A=[1 4 5; 3 -1 8; 12 7 9; 4 10 -5];
(Sorted By Row) B=[1 4 5; -1 3 8; 7 9 12; -5 4 10];
I would like to have the indices of the original matrix appear in the locations of the sorted matrix. For this case it would look like this.
(Original) A=[1 2 3; 1 2 3; 1 2 3; 1 2 3];
(Sorted By Row) B=[1 2 3; 2 1 3; 2 3 1; 3 1 2];
I have tried several different methods but with no luck. Any assistance is appreciated
Thanks

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zohar
zohar 2011-2-21
Hi Daniel
Give us some code and use the code formatting.

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Walter Roberson
Walter Roberson 2011-2-21

2 个投票

[sorted_A, sort_indexes] = sort(A,2);

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Daniel
Daniel 2011-2-21
Thank you, it still isn't quite what I need.I may have worded the question wrong.
Oleg Komarov
Oleg Komarov 2011-2-21
All of your examples are solved with Walter's solution!

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Daniel
Daniel 2011-2-21

0 个投票

A=[ 4 3; 8 4;-1 -5; 2 7];
A1=A
[m,n]=size(A);
for o=1:n
A1=A;
min_val=A(1);
for i=1:n-1
for j=1:m
if A(j,i)>A(j,i+1);
A(j,i+1)=A(j,i);
A(j,i)=A1(j,i+1);
end
end
end
end
A
comp=isreal(A)
if comp==0
A2=abs(A);
else
A2=A;
end
This is what I currently have. The first for loops sort the matrix by row. The second section ensures a real answer.
Daniel
Daniel 2011-2-21

0 个投票

Yes I have tried Walter's solution. When added to my code it yeilds the following.
sort_indexes =
1 2
1 2
1 2
1 2
For these two matrices, it should read:
sort_indexes =
2 1
2 1
2 1
1 2
this is much closer to what I need, but if it worked properly it would display the indexes of the first matrix in the positions in the second matrix. Is there any way to obtain this solution?

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Oleg Komarov
Oleg Komarov 2011-2-21
A=[ 4 3; 8 4;-1 -5; 2 7];
[sorted_A, sort_indexes] = sort(A,2)
gives exactly the second matrix...
Daniel
Daniel 2011-2-21
I apologize, something was wrong with the way that I had input this solution. Both you and Walter are Correct.
Thank you

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