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HOME > Monitoring_and_Data > Oceanic and Atmospheric Data > Reanalysis: Atmospheric Data > wgrib2-import_(bin,ieee,text,grib)

wgrib2: -import_bin, -import_ieee, -import_text, -import_grib


Wgrib2 will decode the grib message and save the decoded grid point values in a floating point array (DATA). The -import options read grid point values from a specified file and replace the values of DATA. The size of DATA and imported grid should match. The -import options are often used to read data that is later written out as a grib message.

Note that the import functions will reset the scaling and precision of the grib writing (new files) to the default (ECMWF-style, 12 bits). Any -set_metadata should be done after the -import functions.

Scan Order

The grib message's scan order is called the "input" scan order (wgrib2 -grid). Wgrib2 converts this to the "output" scan order. (This is the scan order for options like: -bin, -text, -cvs.) The import file needs to be in the "output" scan order. Of course, you can change the output scan order using the -order option.

import Format

The file that you import needs to be in a special format.
  • grib: grib2 message
  • bin: native single point format
  • ieee: IEEE single point format
  • bin: may have a f77 style header depending on the -header option
  • ieee: may have a f77 style header depending on the -header option
  • ieee: may be little or big (default) ending depending on options
  • text: may have a "nx ny" header depending on the -header option (see -text option)


-import_bin data.bin              .. a binary (native format floating point) file
-import_ieee            .. a big-endian 32-bit ieee file
                                     note that the -header and -no_header affect the data file format
-import_text data.txt		  .. a text file
                                     note that the -header and -no_header affect the data file format
-import_grib data.grb		  .. a grib2 file
                                     -g2clib 2 is not supported
                                     conversion to we:sn and we:ns is supported
                                     reads next grid (message or submessage)
                                     -not and -match do not affect -import_grib

Note: grid size (if it can be determined) must match the current grid.

Example 1

wgrib2 IN.grb -bin dump.bin              .. make a binary sequential file of the fields dump.bin             .. alter dump.bin
wgrib2 IN.grb -set_grib_type same -import_bin -set_scaling same same -grib_out
The -import options reads the data for one field and overwrites the current grid point values. The -grib_out option writes a new grib message with the new grid point values.

Example 2: using import to write a grib file

template.grb2             is a single message (field/record) grib2 file with the appropriate grid
                          usually a simple type like 6 hour forecast or analysis
new.bin                   is a binary file with a single field with th same grid as template.grb2

wgrib2 template.grb2 -import_bin new.bin -set_var GEOLAT -set_lev "surface" -set_ftime "anl" \
     -set_date 1999123112 -set_grib_max_bits 24 -set_bin_prec 24 -grib_out new.grb2

This commands writes new.bin as a grib2 file as GEOLAT at 12Z Dec 31, 1999 using 24 bits precision.

See also: -import_netcdf, -set_grib_type, -set_scaling, -undefine, -grib_out, -set_date, -set_ftime, -set_lev, -set_var,

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Page modified: Sep 14, 2016. Sep 23, 2022.
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