sorting according to another vector

Hi,

I have a vector A that doesn't follow any order. I want to sort Matrix B that has the first column of values similar to those of A but in different order. Is it possible to sort B according to A using a single function or should I write many codes to do so?

Answer 1

[Walter Roberson]

Sorry you will have to use multiple calls:

[a_sorted, a_order] = sort(A);
newB = B(a_order,:);

[Jan]

@Danielle: Ok, then I have misunderstood your question. The information that B has "value similar to those of A" is meaningless then - correct?

Answer 2

[Jan]

I'm not sure, if I understand the question correctly. Do you want to bring B in the same order as the unsorted A? Then either sort both vectors and mix their sorting indicies:

[As, Ai] = sort(A);
[Bs, Bi] = sort(B(:, 1));
ABi(Ai) = Bi;

Now ABi is the sorting index to bring B to the order of A:

isequal(A, B(ABi, 1))  % ==> 1

Or let ISMEMBER do this for you:

[dummy, order] = ismember(A, B(:, 1));
isequal(A, B(order, 1))  % ==> 1

Answer 3

[Pramit Biswas]

 function B = sortBlikeA(A,B)
   [~, Ao] = sort(A);
   Bs=sort(B);
   B(Ao)=Bs;
 end

Answer 4

[inzamam shoukat]

Hi every one......i have matrix lets suppose [3 2;1 9]

what i want to do is sort out the only first column in ascending order but problem is how to do it so that corresponding values which is in first row 2 for 3 in second row 9 for 1 change their positions according to the position of values of first column being sorted i.e [1 9; 3 2]...

LIMITATION : sorting operation never applied to second column....

[madhan ravi]

Please ask a separate question

[Steven Lord]

Use sortrows.