read.sealevel {oce} | R Documentation |
Read a data file holding sea level data. BUG: the time vector assumes GMT, regardless of the GMT.offset value.
read.sealevel(file, tz=getOption("oce.tz"), log.action, debug=FALSE)
file |
a connection or a character string giving the name of the file to load. See Details for the types of files that are recognized. |
tz |
time zone. The default value, oce.tz , is set to UTC
at setup. (If a time zone is present in the file header, this will
supercede the value given here.) |
log.action |
if provided, the action item to be stored in the log. (Typically only provided for internal calls; the default that it provides is better for normal calls by a user.) |
debug |
set to TRUE to get debugging information during processing. |
This function starts by scanning the first line of the file,
from which it determines whether the file is in one of two known
formats: type 1, the format used at the Hawaii archive centre, and
type 2, the comma-separated-value format used by the Marine
Environmental Data Service. (The file type is inferred by checking
for the existence of the string Station_Name
on the first line
of the file, indicating type 2.) If the file is in neither of these
formats, the user might wish to scan it directly, and then to use
as.sealevel
to create a sealevel
object.
An object of class
"sealevel"
, which
is a list
containing
data |
A data.frame containing
|
metadata |
A list containing
|
processing.log |
A processing log, in the standard oce format. |
Dan Kelley
The Hawaii archive site at http://ilikai.soest.hawaii.edu/uhslc/datai.html provides a graphical interface for downloading sealevel data in Type 1 (the format is described at ftp://ilikai.soest.hawaii.edu/rqds/hourly.fmt). The MEDS repository provides Type 2 data, at http://www.meds-sdmm.dfo-mpo.gc.ca/meds/Databases/TWL/TWL_inventory_e.htm.
The generic function read.oce
provides an
alternative to this. A sealevel
object may be summarized with
summary.sealevel
. Use plot.sealevel
to
produce a summary plot, and use tidem
to fit a tidal
model to the data.
A "sealevel"
object can also be constructed with
as.sealevel
(and, in fact, read.sealevel
uses
this routine to actually create the "sealevel"
object.)
## Not run: library(oce) # San Francisco data # ftp://ilikai.soest.hawaii.edu/rqds/pacific/hourly/h551a.zip h <- read.sealevel("h551a/h551a01.dat") summary(h) plot(h) ## End(Not run)