How do I sort the rows in one array based on the row order of another array?

I have 2 matrices;

C is 7 x 3 double and G is a 9 x 3 double;

C = [1 1 0; 1 0 1; 0 1 1; 1 0 0; 0 1 0; 0 0 1; 0 0 0];

G = [0 1 1; 0 0 0; 1 0 0; 1 0 1; 0 0 1; 0 0 0; 0 1 1; 1 0 0; 1 0 0];

I’m attempting to create a subset of C (New_C), based on the contents of G, where the order of the rows appearing in New_C are identical to those in C. The proper output would be as follows;

New_C = [ 1 0 1; 0 1 1; 1 0 0; 0 0 1; 0 0 0];

I am able to attain the unique rows in G with the following;

New_C = unique(G, ‘rows’);

But the rows are not in their proper order.

Is there a way to re-order/sort the rows in New_C such that their order matches the rows in C ?

Thanks you.

Answer 1

[James Tursa]

Try this (Caution, untested since I am not on a machine with MATLAB at the moment):

[~,Locb] = ismember(New_C,C,'rows');
New_C = C(sort(Locb),:);

Assumes all rows of New_C can be found in C.

[Brad]

James, thanks for the push!

I had to make a mod and add some code, but it works:

% Find the subset of C
[~,Locb] = ismember(G,C,'rows');
New_C = C(sort(Locb),:);

% Get the unique values and sort
[~,idx]=unique(New_C,'rows');
out=New_C(sort(idx),:);