[ncl-talk] converting shapefile to netcdf

[Dave Allured - NOAA Affiliate]

Correction, the name of this example is shapefiles_14_mask, not just
shapefiles_14.


On Tue, Nov 26, 2019 at 8:57 PM Dave Allured - NOAA Affiliate <
dave.allured at noaa.gov> wrote:

> Example shapefiles_14 is close to what you want.  Please notice these two
> lines.  Their function is to select a particular subset of all the state
> outlines in the example shapefile, then apply a binary mask to the base
> grid "tc_lev0" so that only grid points over the listed states are
> retained.  All grid points outside this list of states are set to missing.
> This demonstrates how to access a subset of a shape file, instead of all
> regions together,
>
>    opt at shape_names = (/"Texas","New
> Mexico","Colorado","Kansas","Oklahoma"/)
>    tc_mask  = shapefile_mask_data(tc_lev0,shp_filename1,opt)
>
> For your application, use this masking function to select one region at a
> time.  Start with a master grid with ERA5 coordinates, set to all zero or
> missing values.  Loop over each region value or region number.  Call the
> function shapefile_mask_data inside the loop, selecting the grid points for
> only one region each time. Use the resulting binary mask to add the
> current region number to the master grid.  When the loop is complete, write
> the master grid with all region numbers to a Netcdf file.
>
>
> On Tue, Nov 26, 2019 at 3:51 PM Amy Hendricks via ncl-talk <
> ncl-talk at ucar.edu> wrote:
>
>> Hello NCL geniuses,
>>
>> I am trying to write a shapefile to netcdf. The shapefile consists of
>> circumpolar Treshnikov regions, and I would like to create a netCDF file
>> that has the region values like tresh(lon,lat) = [region# from shapefile]
>> on the ERA5 grid. All the examples I'm finding are for creating binary
>> masks, and the ncl_convert2nc does not seem to work, at least it doesn't
>> return anything useable.
>>
>> Attached are the ERA5 netCDF file, Treshnikov shapefile, as well as the
>> result of ncl_convert2nc.
>>
>> Thank you in advance,
>>
>> Amy
>>
>
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