hi Hella,
You've come upon a bit of an untested corner of Ferret commands.
With Ferret V6 we added syntax to access information about file
attributes and along with that we put in logic to list file
variables with the command
show var/dset=n varname
Previous to that the show var command only applied to user-defined
variables. This was not well tested (and currently works only
inconsistently).
What you are seeing in this output,
yes? sh var/data rh
rh var # 5 of dataset ./ex_traj2.nc
rh var # 6 of dataset
is the variable number when coordinate variables are not included,
and then the variable number when coordiate variables are included.
So if you did a ncdump -h on the file, I think you'd see a
coordinate variable, then lon, lat, level, press, rh.
I will fix this so that it only lists one line of output. It's
useful so that we can do something like this:
yes? use coads_climatology
yes? use levitus_climatology
yes? let/d=2 sst = temp[gxy=sst[d=1],Z=0]
yes? sho var/d=1 sst
SST var # 1 of dataset
/home/users/tmap/ferret/linux/fer_dsets/data/coads_climatology.cdf
yes? sho var/d=2 sst
SST[D=levitus_climatology] = TEMP[GXY=SST[D=1],Z=0]
I'm not sure the variable number in the file is useful information,
so instead perhaps for the file variable we'd list the units and/or
title.
Ansley
On 5/30/2013 4:00 PM, Hella Riede
wrote:
Dear
ferret list,
from the ferret manual: "SHOW VARIABLES/DATA_SET: Lists variables
associated with the named dataset by DEFINE VARIABLE/DATA_SET="
This works as expected:
yes? let/d=4 test = 1
yes? sh var/data_set=4
TEST[D=ex_traj2] = 1
However, when I used it for information about a file variable in
the following way, I got strange results:
yes? sh var/data rh
rh var # 5 of dataset ./ex_traj2.nc
rh var # 6 of dataset
The first number refers to the position of the queried variable in
the file. But the second number additionally sums up "1" for the
"long_name" attribute when it first appears.
Here is a dump of the file:
yes? sh da 4
4> ./ex_traj2.nc (default)
name title I J K L M N
LAT ... ... ... 1:3 ... ...
LON ... ... ... 1:3 ... ...
LEVEL ... ... ... 1:3 ... ...
PRESS pressure ... ... ... 1:3 ... ...
RH rel hum ... ... ... 1:3 ... ...
TEMP temperat ... ... ... 1:3 ... ...
yes? sh var/data lat
lat var # 1 of dataset ./ex_traj2.nc
lat var # 1 of dataset
yes? sh var/data lon
lon var # 2 of dataset ./ex_traj2.nc
lon var # 2 of dataset
yes? sh var/data level
level var # 3 of dataset ./ex_traj2.nc
level var # 3 of dataset
yes? sh var/data press
press var # 4 of dataset ./ex_traj2.nc
press var # 5 of dataset
yes? sh var/data rh
rh var # 5 of dataset ./ex_traj2.nc
rh var # 6 of dataset
yes? sh var/data temp
temp var # 6 of dataset ./ex_traj2.nc
temp var # 7 of datase
I guess this function IS somehow intended as the output is nicely
configured, but it's certainly also confusing.
Best wishes,
Hella
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