Re: How to read netCDF files with ferret

[Jonathan Callahan <Jonathan.S.Callahan@xxxxxxxx>]

Enils,

You are missing the point of DODS/OPeNDAP access to data.  The files at 
the address you give can be read by Ferret directly.  There is no need 
to download or translate.  The following three Ferret commands give me a 
lovely plot of one particular time series:

yes? use 
"http://stellwagen.er.usgs.gov/cgi-bin/nph-nc/data/time_series/hourly/1012-A1H.cdf";
yes? show data
    currently SET data sets:
   1> 
http://stellwagen.er.usgs.gov/cgi-bin/nph-nc/data/time_series/hourly/1012-A1H.cdf  
(default)
name     title                             I         J         K         L
U_1205   Eastward Velocity                1:1       1:1       1:1       
1:2784
V_1206   Northward Velocity               1:1       1:1       1:1       
1:2784
CD_310   CURRENT DIRECTION (T)            1:1       1:1       1:1       
1:2784
CS_300   CURRENT SPEED (CM/S)             1:1       1:1       1:1       
1:2784
UPR_4001 UPPER ROTOR SPEED                1:1       1:1       1:1       
1:2784
STEAD_4009
         STEADINESS                       1:1       1:1       1:1       
1:2784
T_20     TEMPERATURE (C)                  1:1       1:1       1:1       
1:2784

yes? plot t_20

-- Jon


Enils Bashi wrote:

> Hello,
>
> I am new to ferret and I am having problems reading netcdf files. I got my
> files from
> http://stellwagen.er.usgs.gov/cgi-bin/nph-nc/data/time_series/hourly/ . I
> got them in an ascii format and saved them as netCDF. Are netcdf files text
> files or are they binary?
> Here is what I did:
>
> yes? file/variable=v1 1022-A_cdf_ascii.cdf
> yes? plot v1
> **TMAP ERR: error 0
>             Last or next-to-last record read:
> u_1205.u_1205[u_1205.time=2442673][u_1205.depth=43.5][u_1205.lat=40.8678],
> 7.927
>
>             Data set: .\1022-A_cdf_ascii.cdf
>             Data file: .\1022-A_cdf_ascii.cdf
> yes?
>
> It was not clear to me from the Ferret online documentation how to read a
> file in. The example there was very vague. 
> I would greatly appreciate any help with this problem. A small sample netcdf
> file would be helpful, along with the proper commands to open the file and
> plot some variables.
>
> Thank you in advance,
>
> Enils Bashi
> Programmer
> Veridyne Incorporated
> Annapolis: (410) 267-9833
> ebashi@chesapeakebay.net <mailto:'ebashi@chesapeakebay.net'> 
>