Re: [netcdfgroup] transfering netCDF-file from R to ArcGIS

Great! Many thanks for your help!

Annelie 

-----Ursprüngliche Nachricht-----
Von: David Pierce [mailto:dpierce@xxxxxxxx] 
Gesendet: Wednesday, July 28, 2010 7:12 PM
An: Holzkaemper Annelie ART
Cc: roy.mendelssohn@xxxxxxxx; netcdfgroup@xxxxxxxxxxxxxxxx
Betreff: Re: AW: [netcdfgroup] transfering netCDF-file from R to ArcGIS

Hm, looks like a bug in that version of the library.  Note that ncdf4 is the 
new version and the one I maintain.  ncdf4 supports netcdf version 4, including 
chunking and compression, but also *requires* netcdf-v4 with the full HDF 
support, so it's harder to install.

In any event, this works:

---------------------------------

library(ncdf)
my.nc = open.ncdf("pointtest8.nc", write=TRUE)

dim_id <- my.nc$dim[[1]]

varz = var.def.ncdf("Precipitation","km", list(dim_id), -9999, longname="Daily 
precipitation", prec="double")

my.nc <- var.add.ncdf(my.nc, varz)

att.put.ncdf( my.nc, varz$name, "coordinates", "x y" )

close.ncdf(my.nc)


Regards,

--Dave



annelie.holzkaemper@xxxxxxxxxxxx wrote:
> Hi Dave,
> many thanks for this! Unfortunately I get an error message when I add 
> "att.put.ncdf( my.nc, varz, "coordinates", "x y" )" as you suggested. 
> Here is what I get:
>
>
>> varz = var.def.ncdf("Precipitation","km", list(dim_id), -9999,
> +           longname="Daily precipitation", prec="double")
>> att.put.ncdf( my.nc, varz, "coordinates", "x y")
> [[1]]
> [1] 4
>
>> my.nc <- var.add.ncdf(my.nc, varz)
> Error in var.add.ncdf(my.nc, varz) : Error in create.ncdf, defining var!
>
>
> Annelie
>
>
> -----Ursprüngliche Nachricht-----
> Von: David Pierce [mailto:dpierce@xxxxxxxx]
> Gesendet: Wednesday, July 28, 2010 6:40 PM
> An: Holzkaemper Annelie ART
> Cc: roy.mendelssohn@xxxxxxxx; netcdfgroup@xxxxxxxxxxxxxxxx
> Betreff: Re: [netcdfgroup] transfering netCDF-file from R to ArcGIS
>
> Hi Annelie,
>
> I'm the author of the ncdf package for R.  Thanks for using it!
>
> It looks to me like ArcGIS is using the "coordinate" attribute to 
> figure this information out.  Try adding the following line right 
> after the
> "var.def.ncdf":
>
> att.put.ncdf( my.nc, varz, "coordinates", "x y" )
>
> Regards,
>
> --Dave
>
>
> annelie.holzkaemper@xxxxxxxxxxxx wrote:
>> Hi Roy,
>> thanks for the fast response. I attached the two versions of the 
>> netCDF file (before and after running the R script).
>> I haven't tried to use ncdump yet, but I will.
>>
>> Annelie
>>
>> -----Ursprüngliche Nachricht-----
>> Von: Roy Mendelssohn [mailto:Roy.Mendelssohn@xxxxxxxx]
>> Gesendet: Wednesday, July 28, 2010 5:58 PM
>> An: Holzkaemper Annelie ART
>> Cc: netcdfgroup@xxxxxxxxxxxxxxxx
>> Betreff: Re: [netcdfgroup] transfering netCDF-file from R to ArcGIS
>>
>> Hi Annelie:
>>
>> Since this involves a lot more than netcdf  (R, ArcGIS), a little 
>> more info would help.  Do you access to the ncdump utility?  Can you 
>> do an "ncdump -h" on the files with and without precipitation?  
>> otherwise, if the files aren't toobig, can you send them somehow.
>>
>> Also, the ArcGIS netcdf import is (unfortunately) known to be buggy.
>>
>> -Roy
>>
>> On Jul 28, 2010, at 8:27 AM, annelie.holzkaemper@xxxxxxxxxxxx wrote:
>>
>>> Hi,
>>> I am trying to generate a NetCDF file in R that can be imported in 
>>> ArcGIS using the "Make NetCDF Feature Layer" tool (it is supposed to 
>>> store time series data for each climate station). I have used an 
>>> ArcGIS point-shapefile and converted it into a NetCDF file that I 
>>> can use as a template. This file has 1 dimension (the point ID) and 
>>> 3 variables (x coordinate, y coordinate, elevation). It can easily 
>>> be imported to ArcGIS using "Make NetCDF Feature Layer".
>>> But now I want to add a new variable ("precipitation") to the 
>>> netcdf-file in R:
>>>
>>> >>library(ncdf)
>>> >>my.nc = open.ncdf("C:/temp/pointtest8.nc", write=TRUE)
>>>
>>> >>dim_id <- my.nc$dim[[1]]
>>>
>>> >>varz = var.def.ncdf("Precipitation","km", list(dim_id), -9999,
>>>           longname="Daily precipitation", prec="double")
>>>
>>> >>my.nc <- var.add.ncdf(my.nc, varz)
>>>
>>> >>close.ncdf(my.nc)
>>>
>>>
>>> If I try to import the file modified with R into ArcGIS ("Make 
>>> NetCDF Feature Layer") and choose "precipitation" instead of 
>>> "elevation" as a variable, I can not choose the x and y variables 
>>> (there are no options in the drop down list). However, it is still 
>>> possible to choose the x and y variables for "elevation". So, there 
>>> seems to be some sort of link between the original variable 
>>> "elevation" and the
>>> x- and y-variables that I have not defined for my new variable 
>>> "precipitation" in R. What could be wrong with my definition of the 
>>> new variable?
>>>
>>> I would be very grateful for any suggestions!
>>>
>>> Cheers,
>>> Annelie
>>>
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> netcdfgroup mailing list
>>> netcdfgroup@xxxxxxxxxxxxxxxx
>>> For list information or to unsubscribe,  visit:
>>> http://www.unidata.ucar.edu/mailing_lists/
>>
>> **********************
>> "The contents of this message do not reflect any position of the U.S.
>> Government or NOAA."
>> **********************
>> Roy Mendelssohn
>> Supervisory Operations Research Analyst NOAA/NMFS Environmental 
>> Research Division Southwest Fisheries Science Center
>> 1352 Lighthouse Avenue
>> Pacific Grove, CA 93950-2097
>>
>> e-mail: Roy.Mendelssohn@xxxxxxxx (Note new e-mail address)
>> voice: (831)-648-9029
>> fax: (831)-648-8440
>> www: http://www.pfeg.noaa.gov/
>>
>> "Old age and treachery will overcome youth and skill."
>> "From those who have been given much, much will be expected"
>>
>> _______________________________________________
>> netcdfgroup mailing list
>> netcdfgroup@xxxxxxxxxxxxxxxx
>> For list information or to unsubscribe,  visit:
>> http://www.unidata.ucar.edu/mailing_lists/
>
>
> -------------------------------------------------------------------
> David W. Pierce
> Division of Climate, Atmospheric Science, and Physical Oceanography 
> Scripps Institution of Oceanography
> (858) 534-8276 (voice)  /  (858) 534-8561 (fax)    dpierce@xxxxxxxx
> -------------------------------------------------------------------
>
>
>
>


-------------------------------------------------------------------
David W. Pierce
Division of Climate, Atmospheric Science, and Physical Oceanography Scripps 
Institution of Oceanography
(858) 534-8276 (voice)  /  (858) 534-8561 (fax)    dpierce@xxxxxxxx
-------------------------------------------------------------------




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