DESCRIPTION
Sets key/value pairs in the input grib file and writes each message to the output_grib_file. It fails when an error occurs (e.g. key not found).
USAGE
grib_set [options] grib_file grib_file ... output_grib_file
OPTIONS
-s key[:{s/d/l}]=value,key[:{s/d/l}]=value,...
Key/values to set. For each key a string (key:s) or a double (key:d) or a long (key:l) type can be defined. By default the native type is set.
-r
Repack data. Sometimes after setting some keys involving properties of the packing algorithm a repacking of data is needed. This repacking is performed setting this -r option.
-d value
Set all the data values to "value".
-p key[:{s/d/l}],key[:{s/d/l}],...
Declaration of keys to print. For each key a string (key:s) or a double (key:d) or a long (key:l) type can be requested. Default type is string.
-P key[:{s/d/l}],key[:{s/d/l}],...
As -p adding the declared keys to the default list.
-w key[:{s/d/l}]=value,key[:{s/d/l}]=value,...
Where clause. Set is only executed for grib messages matching all the key/value constraints. If a grib message does not match the constraints it is copied unchanged to the output_grib_file. This behaviour can be changed setting the option -S. For each key a string (key:s) or a double (key:d) or a long (key:l) type can be defined. Default type is string.
-7
Does not fail when the message has wrong length
-S
Strict. Only grib messages matching all the constraints are copied to the output file
-V
Version.
-M
Multi-field support off. Turn off support for multiple fields in single grib message.
-g
Copy GTS header.
-G
GRIBEX compatibility mode.
-T T | B | A
Message type. T->GTS, B->BUFR, A->Any (Experimental). The input file is interpreted according to the message type.
-f
Force. Force the execution not to fail on error.
-v
Verbose.
grib_set examples
To set productDefinitionTemplateNumber=2 only for the fields with productDefinitionTemplateNumber=11
>>grib_set -s productDefinitionTemplateNumber=2 -w productDefinitionTemplateNumber=11 ../data/tigge_pf_ecmwf.grib2 out.grib2
To set productDefinitionTemplateNumber=2 only for the fields for which productDefinitionTemplateNumber is not equal to 11
>>grib_set -s productDefinitionTemplateNumber=2 -w productDefinitionTemplateNumber!=11 tigge_pf_ecmwf.grib2 out.grib2
When a key is not used all the bits of its value should be set to 1 to indicate that it is missing. Since the length (number of octet) is different from a key to another, the value that we have to code for missing keys is not unique. To give an easy way to set a key to missing a string "missing" or "MISSING" is accepted by grib_set as follows:
>>grib_set -s scaleFactorOfFirstFixedSurface=missing,scaledValueOfFirstFixedSurface=MISSING ../data/regular_latlon_surface.grib2 out.grib2
To set scaleFactorOfSecondFixedSurface to missing only for the fields for which scaleFactorOfSecondFixedSurface is not missing:
>>grib_set -s scaleFactorOfSecondFixedSurface=missing -w scaleFactorOfSecondFixedSurface!=missing tigge_pf_ecmwf.grib2 out.grib2
It's possible to produce a grib edition 2 file from a grib edition 1 just changing the edition number with grib_set.At this stage of development all the geography parameters, level and time information is correctly translated, for the productdefinition extra set calls must be done. To do this properly, \ref grib_filter is suggested.
>grib_set -s edition=2 ../data/reduced_gaussian_pressure_level.grib1
With grib edition 2 is possible to compress data using the jpeg algorithm. To change packing algorithm from grid_simple (simple packing) to grid_jpeg (jpeg2000 packing):
>>grib_set -s packingType=grid_jpeg ../data/regular_gaussian_model_level.grib2 out.grib2
It's possible to ask grib_api to calculate the number of bits per value needed to pack a givenfield with a fixed number of decimal digits of precision. For example if we want to pack a temperatureexpressed in Kelvin with 1 digits of precision after the decimal point we can set changeDecimalPrecision=1
>>grib_set -s changeDecimalPrecision=1 ../data/regular_latlon_surface.grib2 ../data/out.grib2rm -f ../data/out.grib2 | true./grib_set -s changeDecimalPrecision=1 ../data/regular_latlon_surface.grib2 ../data/out.grib2