getDataValues: Retrieve data from the observations database

In RObsDat: Data Management for Hydrology and Beyond Using the Observations Data Model

Description

getDataValues allows to query data from the database.

getDataVersions displays all the versions available in the database.

Usage

getDataValues(ID = NULL, from = NULL, to = NULL,
		 tz=c("global", "UTC", "GMT", "0", "local"), Site = NULL,
                 Variable = NULL, Offset = NULL, OffsetType = NULL,
                 CensorCode = NULL, Qualifier = NULL, Method = NULL,
                 Source = NULL, Sample = NULL, DerivedFromID = NULL,
                 QualityControlLevel = NULL, VersionID = NULL,
                 VersionDate = NULL, show.deleted = FALSE, 
		 all.ID = FALSE)

getDataVersions()

Arguments

ID	Unique ID of the DataValue
from	Starting date of the period for which to retrieve the information
to	End date of the period for which to retrieve the information
tz	String indicating whether the data should be obtained in the local or global time zone.
Site	Information about the Site at which the data was observed.
Variable	Information about what variable was observed.
Offset	Information about the offset of the observation. See also OffsetType.
OffsetType	Information about the type of the offset as defined in the OffsetTypes table. See also addOffsetType.
CensorCode	Information about the censor used for the observation.
Qualifier	Qualifying information that can note anything unusual or problematic about individual observations such as, for example, 'holding time for analysis exceeded' or 'incomplete or inexact daily total.'
Method	The method of field data collection, which may specify 'how' a physical observation was made or collected
Source	Reference to the original sources of the data, providing information sufficient to retrieve and reconstruct the data value from the original data files
Sample	Information about physical samples analysed in a laboratory to obtain an observation.
DerivedFromID	Reference to another record in the database, from which a value was derived.
QualityControlLevel	Level of quality controlled applied to a dataset.
VersionID	Data version to be retrieved (see details about version management)
VersionDate	Creation date of the version to be retrieved (see details about version management)
show.deleted	Include records that have been deleted (see details about version management)
all.ID	Boolean: Can the function assume that all values are passed as ID. Reduces number of Database queries. Do not use normally, mainly for internal use.

Details

Raw data often needs to be cleaned before it can be used. RObsDat supports this and allows to reconstruct data modification operations by use of version management. This is valid for deleted and previous versions. What do you want to know in addition?

Value

The function 'getDataValues' returns a spacetime object. Through using the R package spacetime it combine spatial data (sp), time series (xts) and the measurements. Furthermore they are attached ValueIDs, DerivedFromIDs and Metadata of the spacetime object.

Author(s)

Dominik Reusser

See Also

For information how to insert data into the database addDataValues

Examples

getDefaultDB()

#Put data into the database
example(addDataValues)

# Get a list of available variables with ID's)
getMetadata("Variable")$Name 

# Get ID of variable of interest 
var.id <- getID("Variable", "Distance") 

# Get data
data <- getDataValues(Variable="Distance", Site="test site") 
	# returns data object of class 'spacetime' with 3 slots

# Get data values:
data@data #returns values of spacetime-object

RObsDat documentation built on May 29, 2017, 12:07 p.m.