wgrib2: -grib_out
Introduction
The -grib_out option writes the decoded grid to a
specified file in grib2 format. Normally you would use the
-grib option as this option just copies the original grib (sub)message.
The -grib_out option has to repack or compress the decoded grid which
is much slower.
You would only use the
-grib_out option when you have modified
the decoded grid by
the -undefine, -import,
-rpn, or some other option that modifies the
decoded grid.
Use the -set_grib_type option
to specify the grib packing and -set_scaling to specify the scaling.
When the -set_grib_type option is not used, the packing defaults
to simple.
When the -set_scaling option is not used, the scaling is retained
from the input grib message unless a -rpn or -import
option is executed. These two options reset the scaling to the default because they
can alter the range of grid point values.
Usage
-grib_out file_name
Example
$ wgrib2 new.grb2 -undefine out-box -10:10 20:40 -grib_out small.grb2
1:0:d=2005082812:HGT:1000 mb:78 hour fcst:
The above routine sets all the grid points outside the 10W-10E 20N-40N to
undefined and then writes the resultant field as a grib file
in small.grb2. This file will be much smaller than the original field.
Hint: by proper use of the -undefine and -grib_out options, one
should be able to send horizontal boundary conditions for
regional models very very quickly. Imagine just sending
4 lines of horizontal boundary conditions.
Hint: gzip
See also: -text,
-netcdf
-spread
-bin
-ieee
-import_bin, -import_grib, -import_ieee, import_grib
-grib
-rpn
-set_grib_type
-undefine
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