pt.trim {oce}R Documentation

Trim start/end portions of a pT cast

Description

Trim start/end portions of a pT cast.

Usage

pt.trim(x, method="water",parameters=NULL, verbose=FALSE)

Arguments

x A pt object, e.g. as read by read.pt.
method Various methods exist, some of which use parameters:
"water"
Trim data at start and end that seem to be in air (i.e. that have pressure very near 10db, i.e 100kPa.
"time"
Select values only in indicated range of times, provided in POSIX format.
"index"
Select data only if the range of indices given in the two-element parameters list
parameters Depends on method; see above.
verbose If set to TRUE, some debugging information is provided.

Details

The "water" method is mainly for quick and dirty work. In many cases, the user will be working with several files, and so it will make sense to use the "time" method, to synchronize the time series. Normally, notes will have been taken in the field, so no guessing need be done about the time the instruments went in the water. In some cases, though, the time will have to be inferred from the data, and so it might make sense to start by trimming with the "water" method, after which summary.pt is used to find the probably time when the instrument was put into the water.

After the data are trimmed in time, the pressure record is modified by subtracting 10.1325~dbar, the average sea-level pressure.

Value

An object of class "pt", with data having been trimmed in some way, and with the pressure being reduced by mean sea-level pressure.

Author(s)

Dan Kelley

See Also

The pt object may be read with read.pt. plot.pt is very useful in providing guidance for trimming with pt.trim.

Examples

library(oce)
data(pt)
plot(pt)
pt.trimmed <- pt.trim(pt)
plot(pt.trimmed)

[Package oce version 0.1-80 Index]