[ncl-talk] using shapefile to mask out values

[Mary Haley]

Hi Lei,

Thanks for providing the files.  I couldn't tell what the problem was, but
I suggest using the fairly nwe shapefile_mask_data function instead. It
makes your code simpler. This code is provided on the shapefiles examples
page, but I'll attach it here, along with a modified version of your script.

--Mary


On Mon, Oct 27, 2014 at 11:39 AM, Lei Meng <dream916 at gmail.com> wrote:

>  I attached my shapefile and netcdf data file as well as the original ncl
> script. Thanks for your time on this.
>
> Lei
>
> On 10/27/14, 1:17 PM, Mary Haley wrote:
>
>  Lei,
>
>  Without knowing anything about your data, or how the China shapefile is
> structured, I don't know why you have missing values inside the outline.
> Are you getting any errors from running this script?  Is the shapefile a
> "polygon" shapefile or a "polyline" shapefile? If it is a "polyline"
> shapefile, then you may have some areas that aren't fully enclosed, and
> hence "gc_inout" won't work properly.
>
>  It would help if you could also provide the "total_china.shp" and "
> simple.nc" data files.
>
>  Thanks,
>
>  --Mary
>
>
> On Fri, Oct 24, 2014 at 3:33 PM, dream916 <dream916 at gmail.com> wrote:
>
>> Dear All,
>>
>>  I tried to use a China shapefile to mask out values outside of China
>> for a crop dataset. I found that some values inside were also masked out. I
>> attached the screenshot of the shapefile, a pdf file showing the output
>> (top) and the original data (bottom), and my ncl code.  After masking, some
>> pixels inside China were assigned missing value. Any suggestions? Thank you,
>>
>>  Lei
>>
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>
>
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