MATLAB: How to get the row number of a row vector in a matrix

datamatrixrow

Now, master, I have some data, and they are continuous. Each have a coordinate (X, Y) and a row vector [a, b, c]. While, the row vector belongs to a matrix. I want to get the row number and make a new matrix [X, Y, i].
For example：
Here is a point(1,1) , it represents[3,4,5] , wile the matrix is
 [1 1 2; 
  2 2 3; 
  3 3 4; 
  3 4 5; 
  6 6 7; 
  8 8 9]
So , the row number of it is 4. And save [1, 1, 4] into the new matrix.
Then, another point (1,2), it represents[8,8,9]. So It is the sixth line of the matrix. Add [1, 2, 6] to the new matrix.
Question: How can I determine which line the row is in?
How to save the data into the new matrix?

Best Answer

You can find the row with
     A =[
         1     1     2
         2     2     3
         3     3     4
         3     4     5
         6     6     7
         8     8     9];
   B = [8 8 9];
   rowindex = find( ismember(A,B,'rows')>0);
Then you can extract that data from A and save it to another matrix.
For the two cases you present:
    B = [3 4 5; 8 8 9];
    point1  = [1 1];
    point2  = [1 2];
    rowindex = find( ismember(A,B,'rows')>0); 
    C = cat(1,point1,point2,rowindex');
In the matrix, C, the columns are the vectors you want.
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