Decode Table-of-Contents From an rsk File

Decode table-of-contents file from a rsk file, of the sort used by some researchers at Dalhousie University.

Usage

rskToc(dir, from, to, debug = getOption("oceDebug"))

Arguments

dir: name of a directory containing a single table-of-contents file, with .TBL at the end of its file name.
from: optional POSIXct() time, indicating the beginning of a data interval of interest. This must have timezone "UTC".
to: optional POSIXct() time, indicating the end of a data interval of interest. This must have timezone "UTC".
debug: optional integer to control debugging, with positive values indicating to print information about the processing.

Value

A list with two elements: filename, a vector of file names, and startTime, a vector of POSIXct() times indicating the (real) times of the first datum in the corresponding files.

Details

It is assumed that the .TBL file contains lines of the form "File \day179\SL08A179.023 started at Fri Jun 27 22:00:00 2008" The first step is to parse these lines to get day and hour information, i.e. 179 and 023 in the line above. Then, recognizing that it is common to change the names of such files, the rest of the file-name information in the line is ignored, and instead a new file name is constructed based on the data files that are found in the directory. (In other words, the "\\day179\\SL08A" portion of the line is replaced.) Once the file list is complete, with all times put into R format, then (optionally) the list is trimmed to the time interval indicated by from and to. It is important that from and to be in the UTC time zone, because that time zone is used in decoding the lines in the .TBL file.

Sample of Usage


file <- "~/data/archive/sleiwex/2008/moorings/m05/adv/sontek_202h/raw"
table <- rskToc(file,
    from=as.POSIXct("2008-07-01 00:00:00", tz="UTC"),
    to=as.POSIXct("2008-07-01 12:00:00", tz="UTC"))
print(table)

Author

Dan Kelley