Adding rows to matrix based on if-statement in loop

Hey,

I have a matrix with numerical values, however, some data is missing and I have to add some additional rows to the matrix.

The problem is that the rows have to added at a specific place of the matrix since the order of the matrix is important.

I would like to automate the process and work with a loop in which rows are added based on an if-statement which refers to specific values in the matrix

The order of the other rows of the matrix should remain the same.

Any ideas how to implement this?

[Stephen23]

"Any ideas how to implement this?"

Why do you need a loop?

Preallocate the complete output matrix using nan or zeros, then use indexing to allocate all rows of data in one operation.

Answer 1

[Star Strider]

A = randi(9, 7, 5);                                     % Original Matrix
B = randi([51 59], 2, 5);                               % Rows To Be Inserted
Anew = zeros(size(A,1)+size(B,1), size(A,2));           % Output Matrix Preallocation
NewRows = [3 5];                                        % Define Rowss For Insertion
ARows = setdiff(1:size(Anew,1), NewRows);               % Original Rows In New Matrix
Anew(ARows,:) = A;                                      % Copy Rows
Anew(NewRows,:) = B;                                    % Insert Rows

[Kai Friedrich]

Thanks a lot!

[Star Strider]

As always, my pleasure!