how to subtract and insert a data into a matrix

I have 600 by 3 matrix which looks like the following:

     23.456        10.598       1.890
     21.116        11.222      -5.369
     41.963       -10.256      11.235
     54.256        14.589      15.888 
     18.953        20.359      14.523 
     50.142         6.256       9.124
       .             .           .
       .             .           .
       .             .           .
first i want to change the values of each even rows (2,4,6,8...598,600)by the difference between the the values of odd and even rows,i.e row1 - row 2,row3 -row4.......row599-row600. And finally i want to put additional row vector [10.000  10.000  10.000] between each odd and even rows,i.e row1&row2,row3&row4.....row599 & row 600. so finaly i will have 900 by 3 matrix.

[the cyclist]

Just to check exactly what you mean, what should the final values of Row 2 be?

2.3400   -0.6240    7.2590

?

Answer 1

[the cyclist]

See my comment above. If that assumption is correct, then here is one way to get what you want:

A = [23.456        10.598       1.890
     21.116        11.222      -5.369
     41.963       -10.256      11.235
     54.256        14.589      15.888 
     18.953        20.359      14.523 
     50.142         6.256       9.124];

B = 10*ones(3*size(A,1)/2,size(A,2)); 

B(1:3:end,:) = A(1:2:end,:);
B(2:3:end,:) = A(1:2:end,:) - A(2:2:end,:)

This is generalizable to any size for A, as long as it has an even number of rows.

Answer 2

[Jason]

Perhaps something like the following?

% Subtracting and replacing even rows
Data = *original data*;
UpdatedData = zeros(size(Data*1.5,3);
UpdatedData(1:3:end,:) = Data(1:2:end,:);
UpdatedData(3:3:end,:) = Data(1:2:end,:) - Data(2:2:end,:);
% Inserting Rows
UpdatedData(2:3:end,:) = repmat([10 10 10], [size(UpdatedData,1)/3,1]);