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

Sat Oct 17 08:19:15 MDT 2020

Hello Rick,
It works. I have corrected the script to add files individually, so is now clean script and it works. Thank you so much. Cheers
Najib On Friday, October 16, 2020, 02:16:07 PM GMT+1, Rick Brownrigg <brownrig at ucar.edu> wrote:

 I'm assuming you mean this conditional?
exists = isfilepresent(files)if(.not.exists) then ...
That's because "files" is an array, so isfilepresent() returns an array of results. As stated in the error message, NCL requires the conditional expression to evaluate to a scalar.
In this case, you could do something like:
 if (.not.all(exists)) then
However, the original script you sent was a bit muddled as you were trying to first use addfiles, and then trying to add files individually if addfiles failed. I don't know what your script looks like now. You probably want to revisit that logic.
Rick

On Fri, Oct 16, 2020 at 3:21 AM Najib Yusuf <najibgal at yahoo.com> wrote:

Hello Rick,Oh yes..Thank you again. After effecting the corrections, the errors narrowed down to this:
fatal:Conditional statements (if and do while) require SCALAR logical values, see all and any functions.
With this I try changing " If " statement with " where" function but i am missing something and still not executing properly.
fatal:syntax error: where is a function not a procedure; return value must be referenced.

Kindly help.
Thank you
Najib

    On Thursday, October 15, 2020, 06:30:54 PM GMT+1, Rick Brownrigg <brownrig at ucar.edu> wrote:  

 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: <blockquote> Failed to locate resource: /MOPITT/MOP03JM.008/2013.04.01/MOP03JM-201304-L3V95.6.3.he5.dds </blockquote>    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 at ......

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 ifend
Thank you for you help.
Najib Yusuf GaladanciCAR-NASRDA. Nigeria234 80 3871 4158________________________
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