oce (version 0.1-76)

as.sealevel: Coerce data into sea-level dataset

Description

Coerces a dataset (minimally, a sequence of times and heights) into a sealevel dataset.

Usage

as.sealevel(eta,  t,  header=NULL,
  station.number=NA, station.version=NA, station.name=NULL, region=NA,
  year=NA, latitude=NA, longitude=NA, GMT.offset=NA, decimation.method=NA,
  reference.offset=NA, reference.code=NA, sampling.interval=NA)

Arguments

eta

a list of sea-level heights in metres, in an hourly sequence.

t

optional list of times, in POSIXct format. If missing, the list will be constructed assuming hourly samples, starting at 0000-01-01 00:00:00.

header

a character string as read from first line of a standard data file.

station.number

three-character string giving station number.

station.version

single character for version of station.

station.name

the name of station (at most 18 characters).

region

the name of the region or country of station (at most 19 characters).

year

the year of observation.

latitude

the latitude in decimal degrees, positive north of the equator.

longitude

the longitude in decimal degrees, positive east of Greenwich.

GMT.offset

offset from GMT, in hours.

decimation.method

a coded value, with 1 meaning filtered, 2 meaning a simple average of all samples, 3 meaning spot readings, and 4 meaning some other method.

reference.offset

?

reference.code

?

sampling.interval

optional interval between samples, in hours; if not provided, 1 hour is assumed.

Value

• An object of class "sealevel" (for details, see read.sealevel).

Details

The arguments are based on the standard data format, as described at ftp://ilikai.soest.hawaii.edu/rqds/hourly.fmt.

References

ftp://ilikai.soest.hawaii.edu/rqds/hourly.fmt.

See Also

read.sealevel reads data, summary.sealevel summarizes the information. Use plot.sealevel to produce a summary plot, and use tidem to fit a tidal model to the data. Sample sea-level data sets are provided with data(sealevel.hal) and data(sealevel.tuk).

Examples

library(oce)

# Construct a year of M2 tide, starting at the default time
# 0000-01-01T00:00:00.
h <- seq(0, 24*365)
eta <- 2.0 * sin(2*pi*h/12.4172)
sl <- as.sealevel(eta)
summary(sl)

# As above, but start at the Y2K time.
t <- as.POSIXct("2000-01-01") + h * 3600
sl <- as.sealevel(eta, t)
summary(sl)