I would like to add a new column to an existing matrix in file.txt using awk. I have the file
-1.664405 -0.019498 0.487501
-2.210156 0.326547 1.193717
-2.260318 -0.104277 -0.256821
2.189078 -2.103898 1.321050
1.558565 -1.476110 0.967988
1.764428 -2.955372 1.216211
...
...
and I would like to have something like this
O -1.664405 -0.019498 0.487501
H -2.210156 0.326547 1.193717
H -2.260318 -0.104277 -0.256821
O 2.189078 -2.103898 1.321050
H 1.558565 -1.476110 0.967988
H 1.764428 -2.955372 1.216211
...
...
O and H have to vary systematically in this form 100's of times.
Somebody knows how to do it with awk? Thanks in advance