Printing Mat matrix on different lines

Question

I am using C++. I want to print the matrix of a Mat object on different lines like this:

What I have right now is

cout << m <<endl <<endl;

Can anyone help with this please?

sorry i dont know why the last line is not appearing. It's cout < — Steph, Feb 01 '14 at 11:28
I fixed the formatting, but can you explain what m or matrix_f is (declaration)? — wimh, Feb 01 '14 at 11:30
sorry I forgot to mention. "matrix_f" is the name of the Mat object(Mat matrix_f;) — Steph, Feb 01 '14 at 11:40
Do you have just one Mat object and want to print it out, or do you have multiple, and they need to be printed out like in the checker-board pattern you showed in the question? — Anton Poznyakovskiy, Feb 01 '14 at 11:43
i will have 3 Mat matrices which will need to be printed as in the picture in command line — Steph, Feb 01 '14 at 11:44

score 3 · Answer 1 · answered Feb 01 '14 at 11:56

In this case (referring to the comments) you need to print your matrices row-wise. Make use of m.row() and m.at(). Supposed that you have 3x3 matrices as in the image:

for (int i = 0; i < 3; ++i)
{
    Mat row1 = m1.row (i);
    Mat row2 = m2.row (i);
    Mat row3 = m3.row (i);

    // this can be replaced by a loop, I spell it out for the sake of clearness
    cout << row1.at(0, 0) << " " << row1.at (0, 1) << " " << row1.at (0, 2) << "\t"
         << row2.at(0, 0) << " " << row2.at (0, 1) << " " << row2.at (0, 2) << "\t"
         << row3.at(0, 0) << " " << row3.at (0, 1) << " " << row3.at (0, 2) << endl;

}

score 2 · Answer 2 · edited May 23 '17 at 12:11

2

If you are looking to print it to command line, i suggest looking at OpenCV: Matrix Iteration

If you are doing this quite frequently, although not very recommended, you can derive your own Matrix class and override the << operator to print it the way you want it to (as in the link above)

edited May 23 '17 at 12:11

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answered Feb 01 '14 at 11:34

avihayas

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Printing Mat matrix on different lines

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