[ncl-talk] masking the contiguous United States

Ming Chen chen1718 at umn.edu
Sat Jul 4 21:19:10 MDT 2015


Hi all,

I was trying to mask the contiguous United States using a shape file and
the script "shapefile_mask_data.ncl", but got all missing values.

I used ncl 6.2.1. The script I used is here:

;Begins to calculate US averaged NEE
  shp_filename = "coastl_usa.shp"
  opt = True
  opt at minlat = 20
  opt at maxlat = 50
  opt at minlon = 230
  opt at maxlon = 295
  opt at debug  = True
  opt at keep   = True
  opt at loop_check   = True
  data_mask    = shapefile_mask_data(NEE_AVG,shp_filename,opt)
  NEE_scalar   = wgt_areaave(data_mask,1.,1.,0) ;averaged NEE over the
United States


And here is the message I got:
(0)    ==================================================
(0)    Shapefile:         coastl_usa.shp
(0)    Areas of interest: the whole shapefile
(0)    min_lat_chk:       20
(0)    max_lat_chk:       50
(0)    min_lon_chk:       230
(0)    max_lon_chk:       295
(0)    min_lat_data:      -90
(0)    max_lat_data:      90
(0)    min_lon_data:      0
(0)    max_lon_data:      357.5
(0)    13824 data values originally
(0)    Will keep data values inside given shapefile areas
(0)    ==================================================
(0)    0 data values kept
(0)    shapefile_mask_data: elapsed time: 0.930859 CPU seconds.
(0)    ==================================================

I can see there are 13824 data points in my NEE_AVG data. And I have plot
that without problem. Why there was no data masked?

Thanks,
Ming


-- 
Department of Soil, Water and Climate
439 Borlaug Hall 1991 Upper Buford Cir.
St. Paul 55108
MN USA
Office: 612-624-1645
http://www.biometeorology.umn.edu/people_ming.php
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20150704/b1e4e10a/attachment.html 


More information about the ncl-talk mailing list