How to remodify matrix

I have a 6x4 matrix, in which each line has id, x-cor,y-cor, and z-cor for all 3 molecules continuously at time step t1 forllowed by same at t2.

I want to remodify the matrix such that each new file consists only the cord of given molecule

for eg;

1 3.34 4.56 7.86
2 7.09 4.99 5.98
3 8.67 6.90 7.00
1 3.78 2.89 4.78
2 4.78 7.24 6.38
3 4.56 3.10 6.27

I want out put as in file 1as

1 3.34 4.56 7.86
1 3.78 2.89 4.78

and in file 2 as

2 7.09 4.99 5.98
2 4.78 7.24 6.38

and file3 as

3 8.67 6.90 7.00
3 4.56 3.10 6.27

Answer 1

[Dyuman Joshi]

You can use following commands.

Let the 6x4 matrix be 'xyz'.

file1 = xyz(1,:;4,:)
file2 = xyz(2,:;5,:)
file3 = xyz(3,:;6,:)

[Walter Roberson]

MATLAB does not use [] for indexing, and that would not be valid syntax if you changed to () instead of []

Answer 2

[Walter Roberson]

If the matrix is definitely 6 x 4, just use indexing as appropriate

dlmwrite('file1.txt', YourMatrix([1 4], :), ' ')
dlmwrite('file2.txt', YourMatrix([2 5], :), ' ')
dlmwrite('file3.txt', YourMatrix([3 6], :), ' ')

[shravani nethi]

Thanks..