[ncl-talk] Can anyone help me on how to read multiple files from OPeNDAP server

[Rick Brownrigg]

Hi Najib,

You can explore the opendap site with a browser:

https://opendap.larc.nasa.gov/opendap/MOPITT/MOP03JM.008/contents.html

You'll see that for 2013-04, the day is (oddly) 07 instead of 01. Indeed
the pattern seems to be day 01, but there are occasionally other days in
the mix.

Rick



On Thu, Oct 15, 2020 at 11:05 AM Najib Yusuf <najibgal at yahoo.com> wrote:

> Hello Rick,
>
> Thank you Rick. I did print the variables and they return as you pointed
> out, so i corrected the urls to NASA_URL1 = "
> https://opendap.larc.nasa.gov/opendap/MOPITT/MOP03JM.008/2013.01.01/".
> But still i got this error:
>
> syntax error, unexpected WORD_WORD, expecting SCAN_ATTR or SCAN_DATASET or
> SCAN_ERROR.
> The specific error message associated with your request was:</p>
> <blockquote> <p><strong>Failed to locate resource:
> /MOPITT/MOP03JM.008/2013.04.01/MOP03JM-201304-L3V95.6.3.he5.dds
> </strong></p> </blockquote>   <p align="left"> If you think that the server
> is broken (that the URL you submitted should have worked), then please
> contact the OPeNDAP user support coordinator at: <a href="mailto:support@
> ......
>
> Could it be permission issue?
>
> Thank you
>
> Najib
>
>
> On Thursday, October 15, 2020, 05:15:57 PM GMT+1, Rick Brownrigg <
> brownrig at ucar.edu> wrote:
>
>
> Hi,
>
> I don't know for certain the issue, but in building up your list of files
> to be read, you use variables constructed like this:
>
> f_1 = NASA_URL1 + NASA_FILP1
>
> both the URL part and the FILP part contain the filename, so that F_1
> would appear to be incorrectly constructed.  Try printing these variables
> to see what's happening.
>
> Hope that helps...
> Rick
>
>
> On Thu, Oct 15, 2020 at 7:40 AM Najib Yusuf via ncl-talk <
> ncl-talk at mailman.ucar.edu> wrote:
>
> Dear NCL experts,
>
> Using an example in ncl web page (see below) I was able to read a file
> from the OPeNDAP server, i tried to read multiple files (12) using similar
> approach by separating the files with comma like (/"
> https://opendap.larc.nasa.gov/opendap/MOPITT/MOP03JM.008/2013.01.01/MOP03JM-201301-L3V95.6.3.he5
> ","
> https://opendap.larc.nasa.gov/opendap/MOPITT/MOP03JM.008/2013.01.02/MOP03JM-201302-L3V95.6.3.he5
> ","
> https://opendap.larc.nasa.gov/opendap/MOPITT/MOP03JM.008/2013.01.03/MOP03JM-201303-L3V95.6.3.he5"/)
> but it didnt work for me though when i test run the files one after the
> other it reads well. Also, I tried "systemfunc" and "wildcards * but is
> like both doesn't work for OPeNDAP. Kindly guide me how to read multiple
> files from OPeNDAP server. I also tried another approach (see attach file)
> but still didnt work. Thank you
>
>
>  load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
>  load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
>  load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl" ; BRH
>
>  begin
>
> ;--- Using the data files from url
>  NASA_URL  = "
> https://opendap.larc.nasa.gov/opendap/MOPITT/MOP03JM.008/2013.12.01/MOP03JM-201312-L3V95.6.3.he5
> "
>
> ;    f = addfile(NASA_URL,"r")
>   exists = isfilepresent(NASA_URL)
>   if(.not.exists) then
>     print("OPeNDAP test unsuccessful.")
>     print("Either the file doesn't exist, or NCL does")
>     print("not have OPeNDAP cabilities on this system.")
>   else
>     f = addfile(NASA_URL,"r")
>     vnames = getfilevarnames(f)
>     print(vnames)
>   end if
> end
>
> Thank you for you help.
>
> Najib Yusuf Galadanci
> CAR-NASRDA. Nigeria
> 234 80 3871 4158
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