this function can be used to obtain data from a local or remote SQLite database. If the full path with filename is provided in 'SQLiteDB', it will look for that SQLite-file locally. If 'SQLiteDB' is NULL it will establish a connection with a remote server. There is also functionality to use an existing opened data base connection that can be provided in 'use_connection'. For instance, when creating residence patches within a loop of tags and tide ID's. Because establishing a conncection within a for-loop takes a long time, an established connection can be used.
Usage
atl_get_data(
tag,
tracking_time_start,
tracking_time_end,
timezone = "CET",
database = "some_database",
host = "some.host.nl",
username = "someuser",
password = "somepassword",
SQLiteDB = NULL,
use_connection = NULL
)Arguments
- tag
An number representing the WATLAS tag (either in short format e.g. 4 digits or long format with 11 digits). May be passed as a character or a numeric, and will be converted to a character. For example
"31001000001".- tracking_time_start
Character representation of time from which start-point data should be retrieved.
- tracking_time_end
Character time representing the end point corresponding to the above start point.
- timezone
Timezone of tracking_time_start and tracking_time_end. Must be a valid timezone for the as.POSIXct function.
- database
The database name on the host server.
- host
The server address on which the data are stored.
- username
Username to access the server.
- password
Password to access the server.
- SQLiteDB
The full path including the filename of a local SQLite-database whith tracking data. This argument overrules establishing a connection with the remote host.
- use_connection
An R-object with a previously established connection, for instance generated by
RMySQL::dbConnect(RMySQL::MySQL(), user = 'username', password = 'password', dbname = 'database', host = 'host'). This argument overrules making a connection to a local hostSQLiteDBor a remote host.
Value
A data.table of localizations of the specified tag, filtered between
the start and end times.
posID = Unique number for localizations
tag = 4 digit tag number (character)
time = UNIX time (seconds)
datetime = Timestamp in POSIXct (UTC)
x = x-ccordinates in meters (UTM 31 N)
y = y-ccordinates in meters (UTM 31 N)
nbs = Number of Base Stations used in calculating coordinates
varx = Variance in estimating x-coordinates
vary = Variance in estimating y-coordinates
covxy = Co-variance between y- and y-coordinates