eseis (version 0.6.0)

aux_getevent: Load seismic data of a user-defined event

Description

The function loads seismic data from a data directory structure (see aux_organisecubefiles()) based on the event start time, duration, component and station ID.

Usage

aux_getevent(
  start,
  duration,
  station,
  component = "BHZ",
  format = "sac",
  dir,
  simplify = TRUE,
  eseis = TRUE,
  try = FALSE,
  silent = TRUE
)

Value

A list object containing either a set of eseis

objects or a data set with the time vector ($time) and a list of seismic stations ($station_ID) with their seismic signals as data frame ($signal). If simplify = TRUE (the default option) and only one seismic station is provided, the output object containseither just one eseis object or the vectors for $time and $signal.

Arguments

start

POSIXct value, start time of the data to import.

duration

Numeric value, duration of the data to import, in seconds.

station

Character value, seismic station ID, which must correspond to the ID in the file name of the data directory structure (cf. aux_organisecubefiles).

component

Character value, seismic component, which must correspond to the component name in the file name of the data directory structure (cf. aux_organisecubefiles). Default is "BHZ" (vertical component of a sac file).

format

Character value, seismic data format. One out of "sac" and "mseed". Default is "sac".

dir

Character value, path to the seismic data directory.

simplify

Logical value, option to simplify output when possible. This basically means that if only data from one station is loaded, the list object will have one level less. Default is TRUE.

eseis

Logical value, option to read data to an eseis object (recommended, see documentation of aux_initiateeseis), default is TRUE

try

Logical value, option to run the function in try-mode, i.e., to let it return NA in case an error occurs during data import. Default is FALSE.

silent

Logical value, option to suppress messages during function execution. Default is TRUE.

Author

Michael Dietze

Details

The function assumes complete data sets, i.e., not a single hourly data set must be missing. The time vector is loaded only once, from the first station and its first component. Thus, it is assumed that all loaded seismic signals are of the same sampling frequency and length.

Examples

## set seismic data directory
dir_data <- paste0(system.file("extdata", package="eseis"), "/")

## load the z component data from a station
data <- aux_getevent(start = as.POSIXct(x = "2017-04-09 01:20:00", 
                                        tz = "UTC"), 
                      duration = 120,
                      station = "RUEG1",
                      component = "BHZ",
                      dir = dir_data)                       
## plot signal
plot_signal(data = data)

## load data from two stations
data <- aux_getevent(start = as.POSIXct(x = "2017-04-09 01:20:00", 
                                        tz = "UTC"), 
                     duration = 120,
                     station = c("RUEG1", "RUEG2"),
                     component = "BHZ",
                     dir = dir_data)

## plot both signals
par(mfcol = c(2, 1))
lapply(X = data, FUN = plot_signal)