Stream-class: Class '"Stream"'

In IRISSeismic: Classes and Methods for Seismic Data Analysis

Class "Stream"

Description

A Stream object containing a list of Trace objects.

Objects from the Class

Objects are typically created by calls to getDataselect.

Slots

url:

Object of class "character": URL request used to generate this Stream.

requestedStarttime:

Object of class "POSIXct": starttime used when requesting data with getDataselect.

requestedEndtime:

Object of class "POSIXct": endtime used when requesting data with getDataselect.

act_flags:

Object of class "integer": Accumulators for the act_flags bits in each miniSEED record.

io_flags:

Object of class "integer": Accumulators for the io_flags bits in each miniSEED record.

dq_flags:

Object of class "integer": Accumulators for the dq_flags bits in each miniSEED record.

timing_qual:

Object of class "numeric": Average timing quality associated with miniSEED records.

traces:

Object of class "list": List of Trace objects.

Methods

getGaps

signature(x="Stream"): returns information on data dropouts between Traces; see getGaps

getUpDownTimes

signature(x="Stream", min_signal="numeric", min_gap="numeric"): returns a vector of datetimes associated with channel up/down transitions; see getUpDownTimes

length

signature(x="Stream"): returns the total number of data points in all Traces

max

signature(x="Stream"): returns the overall data maximum for all data in all Traces

median

signature(x="Stream", na.rm= "logical"): returns the overall data median for all data in all Traces

mean

signature(x="Stream"): returns the overall data mean for all data in all Traces

mergeTraces

signature(x="Stream", fillMethod="fillNA"): returns a new Stream object where all Traces have been merged into a single Trace mergeTraces

min

signature(x="Stream"): returns the overall data minimum for all data in all Traces

multiplyBy

signature(x="Stream", y="numeric"): returns a new Stream object where the data in every Trace have been multiplied by y; see multiplyBy

parallelLength

signature(x="Stream"): returns a vector of data lengths, one for each Trace

parallelMax

signature(x="Stream"): returns a vector of data maxima, one for each Trace

parallelMedian

signature(x="Stream", na.rm= "logical"): returns a vector of data medians, one for each Trace

parallelMean

signature(x="Stream"): returns a vector of data means, one for each Trace

parallelMin

signature(x="Stream"): returns a vector of data minima, one for each Trace

parallelRms

signature(x="Stream"): returns a vector of RMS calculations, one for each Trace; see rmsVariance

parallelRmsVariance

signature(x="Stream"): returns a vector of RMS variance calculations, one for each Trace; see rmsVariance

parallelSd

signature(x="Stream", na.rm="logical"): returns a vector of standard deviation calculations, one for each Trace

plot

signature(x="Stream"): default plot of the merged Traces in a Stream with appropriate labeling

plotUpDownTimes

signature(x="Stream", min_signal="numeric", min_gap="numeric"): plots the times at which a Stream transitions from data collection to non-collection (on/off); see getUpDownTimes

rms

signature(x="Stream"): returns the overall Root Mean Square amplitude for all data in all Traces; see rmsVariance

rmsVariance

signature(x="Stream"): returns the overall RMS variance for all data in all Traces; see rmsVariance

sd

signature(x="Stream", na.rm="logical"): returns the overall standard deviations for all data in all Traces

slice

signature(x="Stream", starttime="POSIXct", endtime="POSIXct"): returns a new Stream sliced out of an existing Stream (see slice)

uniqueIds

signature(x="Stream"): returns a vector of SNCLQ identifiers, one for each Trace

Note

The Stream object is inspired by the Stream class found in the python ObsPy package (https://docs.obspy.org/packages/autogen/obspy.core.stream.Stream.html).

The miniSEED flags and timing_qual values are described in the SEED manual (https://www.fdsn.org/seed_manual/SEEDManual_V2.4.pdf). The "accumulators" contain counts of the number of times each bit flag was set during the parsing of a miniSEED file. These attributes are retained primarily for assessing data quality issues within the EarthScope.

The following code documentation describes how each of the flags is used within miniSEED files:

  # act_flags
  # [1] Calibration signals present
  # [2] Time correction applied
  # [3] Beginning of an event, station trigger
  # [4] End of an event, station detrigger
  # [5] A positive leap second happened in this record
  # [6] A negative leap second happened in this record
  # [7] Event in progress
  # [8] Undefined bit set

  # io_flags
  # [1] Station volume parity error possibly present
  # [2] Long record read (possibly no problem)
  # [3] Short record read (record padded)
  # [4] Start of time series
  # [5] End of time series
  # [6] Clock locked
  # [7] Undefined bit set
  # [8] Undefined bit set

  # dq_flags
  # [1] Amplifier saturation detected
  # [2] Digitizer clipping detected
  # [3] Spikes detected
  # [4] Glitches detected
  # [5] Missing/padded data present
  # [6] Telemetry synchronization error
  # [7] A digital filter may be charging
  # [8] Time tag is questionable

Author(s)

Jonathan Callahan [e-mail]

Examples

## Not run: 
# Open a connection to EarthScope webservices
iris <- new("IrisClient")

starttime <- as.POSIXct("2012-01-24", tz="GMT")
endtime <- as.POSIXct("2012-01-25", tz="GMT")

# Get the waveform
st <- getDataselect(iris,"AK","PIN","","BHZ",starttime,endtime)
min(st)
median(st)
mean(st)
max(st)
sd(st)
rms(st)
rmsVariance(st)

## End(Not run)

IRISSeismic documentation built on April 4, 2025, 2:14 a.m.