Re: write cdf file using a list of selected indices

[Ansley Manke <ansley.b.manke@xxxxxxxx>]

Hi Billy,
I'm not sure I understand what your data is like,  but I was able to 
concoct an example where a t-z variable has missing data at some of the 
depths at different times, and it's true that the COMPRESSL function 
just compresses along the L axis at each depth, so it doesn't preserve 
the depth profile at each time.  Not the behavior you need.

Would a sequence like this do what you want?  I haven't tested what the 
append does but I think something like this should do the job.

 save/file=outfile.nc  lonsi, latsi, julsi

 let npts = `ytrack,return=lend`
 repeat/range=1:`npts`/name=m \
    (if ytrack[L=`m`] then \
     save/append/file=outfile.nc temp[L=`m`])


Thanks for the note about the compress*_by functions. We'll work on 
adding to the documentation on them.

Ansley


William S Kessler wrote:

> I have a large cdf file consisting of a (z,t) temperature grid with
> associated (time-index-only) grids of lats, lons and julian dates. I
> have defined a subset of these, which are defined by a latitude flag
> (ytrack) existing or not:
>
> let tempsi = if ytrack then temp  ! only exists at selected ytrack
> let lonsi = if ytrack then lon
> let latsi = if ytrack then lat
> let julsi = if ytrack then jul
>
> I want to write just the selected ones to a new cdf file.
> COMPRESSL works fine for the three 1-d variables, but not for the (z,t)
> temperature grid, because the temperature profiles are not all of the
> same depth range (as a result COMPRESSL pushes all of them to lower
> indices at each depth and does not keep profiles intact). How can I SAVE
> (ideally all in a single cdf file) just the temp, lon, lat and jul data
> that exist?
>
> By the way, the description of COMPRESSI_BY in the documentation does
> not give enough information for me to figure out what this does.
>
> Billy K
>
>