Using GrADS to retrieve HYCOM data

[James T. Potemra]

Hi Mark:

Your variable constraints look more like Matlab syntax to me.  If you
simply use sdfopen http://...... .nc (truncate
everythins from the ? to the end) it should work.  You'll then have
access to the entire data file and can just
'set x 1500 2300', 'set y 1750 2169', and so on, then 'd mld'

Jim

Mark Hess wrote:
> Can anyone tell me what I am doing wrong here?  At this point I'm just
> trying to get a file off of the HYCOM server.  I used the server
> http://hycom.coaps.fsu.edu/opendap/nph-dods/datasets/hycom/global/GLBa0.08_rect/data/2d/rarchv.2009_125_00_2d.nc.html to
> generate the URL string below, but am obviously missing something
> quite basic (I'm an inexperienced GrADS user and brand new to
> OPeNDAP). Will I need to create a custom .ctl file to access and
> display these data or am I simply using the sdfopen command incorrectly?
>
> I am running GrADS version 2.0.a3.  My command and result are below.
>
> ga-> sdfopen
> http://hycom.coaps.fsu.edu/opendap/nph-dods/datasets/hycom/global/GLBa0.08_rect/data/2d/rarchv.2009_125_00_2d.nc?mld[0:1:0][1750:1:2169][1500:1:2300]
>
> Scanning self-describing file:
> http://hycom.coaps.fsu.edu/opendap/nph-dods/datasets/hycom/global/GLBa0.08_rect/data/2d/rarchv.2009_125_00_2d.nc?mld[0:1:0][1750:1:2169][1500:1:2300]
> gaopnc error: nc_open failed to open file
> http://hycom.coaps.fsu.edu/opendap/nph-dods/datasets/hycom/global/GLBa0.08_rect/data/2d/rarchv.2009_125_00_2d.nc?mld[0:1:0][1750:1:2169][1500:1:2300]
> read_metadata: gaopnc failed
> gadsdf: Couldn't ingest SDF metadata.
> ga->
> Mark
>
>     ----- Original Message -----
>     *From:* Dan Martin <mailto:Dan_Martin at BUOYWEATHER.COM>
>     *To:* GRADSUSR at LIST.CINECA.IT <mailto:GRADSUSR at LIST.CINECA.IT>
>     *Sent:* Thursday, April 30, 2009 7:40 PM
>     *Subject:* Re: Using GrADS to retrieve HYCOM data
>
>     The full HYCOM data is on a curvilinear grid that I haven't been
>     able to
>     make work in grads. They set up a linear grid for grads users by
>     cutting
>     off pre-gridded section above 48 degrees north.
>
>     http://hycom.coaps.fsu.edu/opendap/nph-dods/datasets/hycom/global/GLBa0.08_rect/data/
>
>     The update schedule is a bit irregular and the server is not alway up,
>     but nice data when it is there.
>
>     If anyone has the curvilinear grid version working in grads, any tips
>     would be nice.
>
>     Dan
>
>     Mark Hess wrote:
>     > Has anyone out there used GrADS to retrieve and display data
>     from the
>     > HYCOM OPeNDAP near real-time data server
>     > http://hycom.coaps.fsu.edu/thredds/dodsC/glb_nrt_analysis.html?
>     >
>     > I am hoping to use GrADS to retrieve mixed layer depth data from
>     this
>     > server, but not real clear on the http/OPeNDAP string I would use to
>     > download the file (whether it be ASCII or binary).  If you have done
>     > this and could send a sample script or command showing the http
>     > line that would be much appreciated.
>     >
>     > Thanks,
>     >
>     > Mark
>     >
>