[ncl-talk] Reading ECMWF THREDDS data using OPENDAP

Fri Sep 11 16:21:50 MDT 2015

Hi David,
It is likely that NCL will need some updates to work with
access-restricted sites such as this one. I am going to look into it.
 -dave


On Fri, Sep 11, 2015 at 3:40 PM, Vollaro, David <dvollaro at albany.edu> wrote:
> Hi Mary,
>
>
>
> No my issue was never resolved.  I contacted Dave Stepaniak about this and
> he speculates that it is possible, however, trying to add my RDA
> username/passwd to the NCL Opendap call is another issue.  I can set my
> cookies using wget to remotely access an RDA dataset but doing this in NCL
> is proving problematic.  I have decided to run a NCL script on geyser to
> access the data on glade ans sftp it back to me.  However, I am running into
> another issue.  If I transfer the data using NETCDF3 it works OK.  However
> when I use the setfileoption to netcdf4 the file fills with missing values
> on my local system(although it is Ok on glade).  I am assuming that it is
> some issue with sftp.
>
>
>
> ;  setfileoption("nc","Format","NetCDF3")
>
> ;  setfileoption("nc","Format","NetCDF4")
>
>
>
>
>
> I have remotely access the RDA datsets
>
> From: Mary Haley <haley at ucar.edu>
> Sent: Friday, September 11, 2015 5:14 PM
> To: Vollaro, David
> Cc: ncl-talk at ucar.edu
> Subject: Re: [ncl-talk] Reading ECMWF THREDDS data using OPENDAP
>
>
>
> Dave,
>
>
>
> I didn't see any response to this. Was it ever resolved?
>
>
>
> The issue is that these files are not being served by an OPeNDAP server, and
> hence you can't open them with an OPeNDAP-enabled client.
>
>
>
> --Mary
>
>
>
>
>
>
>
> On Fri, Sep 4, 2015 at 3:29 PM, Vollaro, David <dvollaro at albany.edu> wrote:
>
> Hi,
>
>
>
> I am trying to read an ECMWF dataset from the NCAR RDA THREDDS servver using
> NCL.
>
> I am using the example OPENDAP script from NCL but am having trouble
> accessing the data.
>
>
>
> The snippet of the NCL script I am using is below, as is the link to the
> datasset I am trying to access.
>
> I have sucessfully accessed data using OPENDAP before, so I am hoping that
> it is just an incorrecct
>
> link-id.  I am running 6.1.2...Thanks...
>
>
>
> Dave Vollaro
>
>
>
> --------------- code snippet --------------
>
>   url = "http://rda.ucar.edu/thredds/fileServer/aggregations/e/ds627.0/15/"
> filename = url +
> "ERA_Interim_atmospheric_model_forecast_for_surface-198808/files/ei.oper.fc.sfc.regn128sc.1988080100"
> print(filename)
> ;***********************************************
> ;  DATA SOURCE
> ;***********************************************
>
>   exists = isfilepresent(filename)
>   if(.not.exists) then
>     print("OPeNDAP isfilepresent test unsuccessful.")
>     print("File doesn't exist or NCL doesn't have OPeNDAP ability on this
> system")
>   else
>     print("OPeNDAP isfilepresent test successful.")
>     file_nc = addfile(filename,"r")
>   end if
>   names = getfilevarnames(file_nc)          ;Get the variable names in the
>   print(names)                               ;GRIB file and print them out.
> end
>
>
>
> --------- end snippet-------
>
>   link:
> http://rda.ucar.edu/thredds/catalog/aggregations/e/ds627.0/15/ERA_Interim_atmospheric_model_forecast_for_surface-198808/catalog.html?dataset=aggregations/e/ds627.0/15/ERA_Interim_atmospheric_model_forecast_for_surface-198808/files/ei.oper.fc.sfc.regn128sc.1988080100
>
>
>
>
> error:
>
> (0)
> http://rda.ucar.edu/thredds/fileServer/aggregations/e/ds627.0/15/ERA_Interim_atmospheric_model_forecast_for_surface-198808/files/ei.oper.fc.sfc.regn128sc.1988080100
> syntax error, unexpected WORD_WORD, expecting SCAN_ATTR or SCAN_DATASET or
> SCAN_ERROR
> context: <html^><head><title>Apache Tomcat/7.0.63 - Error
> report</title><style><!--H1
> {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:22px;}
> H2
> {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:16px;}
> H3
> {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:14px;}
> BODY
> {font-family:Tahoma,Arial,sans-serif;color:black;background-color:white;} B
> {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;}
> P
> {font-family:Tahoma,Arial,sans-serif;background:white;color:black;font-size:12px;}A
> {color : black;}A.name {color : black;}HR {color : #525D76;}--></style>
> </head><body><h1>HTTP Status 401 - </h1><HR size="1"
> noshade="noshade"><p><b>type</b> Status report</p><p><b>message</b>
> <u></u></p><p><b>description</b> <u>This request requires HTTP
> authentication.</u></p><HR size="1" noshade="noshade"><h3>Apache
> Tomcat/7.0.63</h3></body></html>
> ncopen: filename
> "http://rda.ucar.edu/thredds/fileServer/aggregations/e/ds627.0/15/ERA_Interim_atmospheric_model_forecast_for_surface-198808/files/ei.oper.fc.sfc.regn128sc.1988080100":
> NetCDF: Malformed or inaccessible DAP DDS
> (0)     OPeNDAP isfilepresent test unsuccessful.
> (0)     File doesn't exist or NCL doesn't have OPeNDAP ability on this
> system
>
>
>
>
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