This component reads data directly from the main archive. It is normally used as the start of a data extraction and processing chain. Data generated by it are not in a human readable format. To display the data use a component like da.export instead.
Usage
da.get [station] variables times [archive]
Arguments
- station
-
This argument is used to specify the station used to look up variables that do not include a station as part of an archive read specification. The station is the three letter GAW station code of the location, such as
BND
. The argument accepts multiple stations specified as regular expressions and separated by:
or;
or,
. For exampleBND,MLO
and(BND|MLO)
are two ways of selecting both the BND and MLO stations.The special value
allstations
may also be specified to select all stations. - variables
-
This argument may be split into multiple actual program arguments. Each part consists of one or more variable specifications separated by
,
(commas). The station and archive used if none are explicitly given are defined in the other arguments or inferred from system defaults. For example simplyBsB_S11
selects the blue scattering from the S11 instrument and returns all cut sizes and metadata. If instead::BsB_S11:pm10
is used then only PM10 scattering is returned. That is, the selection specifies "any" station and archive (the defaults are set in the other arguments) then requires that it has the "PM10" flavor. A specification such asbnd:BsB_S11,thd:BsB_S11
allows for data selection from multiple stations.This may also be used to select a "record" type alias such as "S11a". In this mode all the variables defined in the alias are returned.
Finally the special value
everything
can be used to select all available data for the given station(s) and archive(s). - times
-
This argument may be split into multiple actual program arguments. This full list of time arguments defines a time bounds list that sets the range of data queried. The final resulting data are clipped to the given time bounds but any values that intersect them are returned.
- archive
-
This argument is used to specify the archive used to look up variables that do not include an archive as part of an archive read specification. The archive is the internal name, such as
raw
orclean_meta
. The argument accepts multiple archives specified as regular expressions and separated by:
or;
or,
. For exampleraw(_meta)?
selects both theraw
andraw_meta
archives.The special value
allarchives
may also be used to select all available archives.
Examples
- General usage
-
This retrieves the record S11a (which is an alias for several relevant nephelometer parameters) for the station brw from 2010-01-01 to 2010-01-10 from the raw archive.
da.get brw S11a 2010-01-01 2010-01-10
- Specifying a list of variables
-
This retrieves the given variables from the clean archive and also demonstrates more relaxed time specification.
da.get brw BsB_S11,BsG_S11,BsR_S11 2010 5 2010 7 clean
- Advanced variable selection
-
This retrieves only variable BsB_S11 from the raw archive of the implied station (from the working directory or other information) but only the PM1 cut size data. It also retrieves the variable from the spo clean archive with both cut sizes. The data are retrieved from 2010-01-01 to 2010-01-02.
da.get ::BsB_S11:pm1 spo:clean:BsB_S11 2010:1