write cdf file using a list of selected indices

[William S Kessler <William.S.Kessler@xxxxxxxx>]

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