How to replace some values of a variable?

Greetings,
How do I change some values of a particular variable in a bunch of my netcdf files?
Any advice would be greatly appreciated.  Here's what I wish to do:

Change variable "zaxis = 1, 2, 3;" to "zaxis = 0.3, 0.6, 0.9;" for the file below:

netcdf filex {
dimensions:
        two = 2 ;
        three = 3 ;
        time = UNLIMITED ; // (15 currently)
        xaxis = 1320 ;
        yaxis = 1482 ;
        zaxis = 3 ;
        zip2 = 1117087 ;
        zip3 = 5587693 ;
variables:
        int zaxis(zaxis) ;
                zaxis:long_name = "coordinate variables of zaxis" ;
                zaxis:units = "sigma_level" ;
                zaxis:figure = "na" ;
                zaxis:positive = "down" ;
…
zaxis = 1, 2, 3 ;

I  tried the following command but the command unexpectedly changed other things in my file.  For example, some dimensions got deleted; zaxis variable got deleted.

%  ncap -s 'zaxis=.33;zaxis=.66;zaxis=.99' filex.nc  x.nc

I got:

netcdf x {
dimensions:
        time = UNLIMITED ; // (15 currently)
        xaxis = 1320 ;
        yaxis = 1482 ;
        zaxis = 3 ;
variables:
        double zaxis ;
…
zaxis = 0.33 ;

Thanks.
-chk

Use ncap2. Both of these should work:

ncap2 -s 'zaxis/=3.3333333' filex.nc x.nc
ncap2 -s 'zaxis(:)={0.33,0.66,0.99}' filex.nc x.nc

cz

Many thanks, Charlie.
-chk

Hi, I have the same problem.
I would like to replace all the null values ​​with a "zero" value:

from

netcdf current {
dimensions:
...
...
variables
float current (lon, lat, time)
...
...

current:
, , , , 1, , , , , , , 3, , , 25, , , , , _

in

current:
0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 3, 0, 0, 25, 0, 0, 0,......

thanks
Emanuele

ncap2 where() syntax can do this:
http://nco.sf.net/nco.html#where
cz