MATLAB: I have created a matrix out of another matrix. I now want to find the index values for those specific numbers in the 2nd matrix FROM the 1st matrix. How to go about doing that

indexingMATLABmatrix

matrix_1=[11 50;
    12 80;
    13 120;
    14 140;
    15 180;
    16 210;
    17 250;
    18 275;
    19 325;
    20 400;
    19 350;
    18 300;
    17 240;
    16 200;
    15 190;
    14 150;
    13 100;
    12 75;
    10 25]
matrix_2=[11 50;
    20 400;
    10 25]
I want to create another matrix that lists the index numbers for matrix 2. So it would look something like idx=[1; 10; 19]

Best Answer

[ex, index] = ismember(matrix_2, matrix_1, 'rows')
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