Problem with ncdf4 where on windows machines doesn't work

[sckott]

at least for gefs fxns I get an error that the file type can not be read, the .grib file type, see if this can be fixed

[potterzot]

I'm a little confused on this, is it specific to windows and to gefs? Can you give me a reproducible example to work from?

[sckott]

Sure, I'll try it again on windows and paste in the error I get

[sckott]

@potterzot e.g,

lat <- 46.28125
lon <- -116.2188
gefs("Temperature_height_above_ground_ens", lat, lon, date = format(as.Date(Sys.time()) - 1, "%Y%m%d"), forecast_time = "1800", ens_idx=2:4, time_idx=1:8)

Error in R_nc4_open: NetCDF: Unknown file format
Error in ncdf4::nc_open(gefs_url):
    Error in nc_open trying to open file http://thredds.ucar.edu/thredds/dodsc/grib/NCEP/GEFS/Global_1p0deg_Ensemble/members/GEFS_Global_1p0deg_Ensemble_20160120_1800.grbi2

[sckott]

That grib2 file format is causing problems, never heard of that format, not sure where to look for solution

[potterzot]

some climate data is stored in it. I'll look at it, should be able to fix
quickly. Thanks for bringing it to my attention and thanks for the example!

---

Nicholas Potter
http://potterzot.com

On Thu, Jan 21, 2016 at 11:15 AM, Scott Chamberlain <
notifications@github.com> wrote:

That grib2 file format is causing problems, never heard of that format,
not sure where to look for solution

—
Reply to this email directly or view it on GitHub
#127 (comment).

[sckott]

@potterzot let me know when you get a fix for this, hoping to get the next patch version https://github.com/ropensci/rnoaa/milestones/v0.5.2 pushed soon

[potterzot]

@sckott Strange, it works fine on linux. I hope to make it happen this weekend, and push an update in the next couple of days. Will that work?

[sckott]

Sounds good

[potterzot]

I think this is an upstream bug. Bypassing rnoaa and using ncdf4 directly, I have no problem on linux but can't access the file on windows.

On Linux:

library(ncdf4)
gefs_url <- "http://thredds.ucar.edu/thredds/dodsC/grib/NCEP/GEFS/Global_1p0deg_Ensemble/members/GEFS_Global_1p0deg_Ensemble_20160120_1800.grib2"

con <- nc_open(gefs_url)
vars <- names(con$var)
vars[1:5]
#> [1] "reftime"                          "LatLon_Projection"               
#> [3] "time_bounds"                      "pressure_difference_layer_bounds"
#> [5] "depth_below_surface_layer_bounds"

On Windows:

...
con <- nc_open(gefs_url)
Error in R_nc4_open: NetCDF: Unknown file format
Error in nc_open(t_url) : 
  Error in nc_open trying to open file http://thredds.ucar.edu/thredds/dodsC/grib/NCEP/GEFS/Global_1p0deg_Ensemble/members/GEFS_Global_1p0deg_Ensemble_20160120_1800.grib2

If this makes sense, I'll submit a bug to ncdf4.

What would you like to do with the gefs code in the meantime? I can put a notice in that says it doesn't work for windows, or if you would prefer something else just let me know.

[sckott]

thanks for looking in to this 👍

how about we just stop on windows, for all applicable gefs functions, e .,g, put this code in

if (is_windows()) stop("gefs not implemented on windows yet", .call = FALSE)

[sckott]

temporary fix in #133 , closing this, will open new issue to remind us to fix this

[mauritzvdworm]

Any update in getting the gefs data using a windows machine?

[sckott]

@mauritzvdworm I don't think so , follow #134 for updates on this issue