R: Read a met File

read.met {oce} | R Documentation

## Read a met File

### Description

Reads a comma-separated value file in the format used by the Environment Canada [1]. The agency does not publish a format for these files, so this function was based on a study of a few sample files, and it may fail for other files, if Environment Canada changes the format.

### Usage

    read.met(file, type = NULL, skip, tz = getOption("oceTz"),
      debug = getOption("oceDebug"))

### Arguments

`file` | a connection or a character string giving the name of the file to load.
`type` | if `NULL`, then the first line is studied, in order to determine the file type. If `type="msc"`, then a file as formatted by Environment Canada is assumed.
`skip` | optional number of lines of header that occur before the actual data. If this is not supplied, `read.met` scans the file until it finds a line starting with `"Date/Time"`, and considers all lines above that to be header.
`tz` | timezone assumed for time data
`debug` | a flag that turns on debugging. Set to 1 to get a moderate amount of debugging information, or to 2 to get more.

### Value

An object of `class` `"met"`, of which the `data` slot contains vectors `time`, `temperature`, `pressure`, `u`, and `v`. The velocity components have units m/s and are the components of the vector of wind direction. In other words, the oceanographic convention on velocity is employed, not the meteorological one; the weather forecaster's "North wind" has positive `v` and zero `u`. In addition to these things, `data` also contains `wind` (in km/h), taken straight from the data file.

### Note

There seem to be several similar formats in use, so this function may not work in all cases.

### Author(s)

Dan Kelley

### References

1. Environment Canada website for Historical Climate Data http://climate.weather.gc.ca/index_e.html

### See Also

Other things related to `met` data: `[[,met-method`, `[[<-,met-method`, `as.met`, `download.met`, `met-class`, `met`, `plot,met-method`, `subset,met-method`, `summary,met-method`

### Examples

    ## Not run:
    library(oce)
    # Recreate data(met) and plot u(t) and v(t)
    metFile <- download.met(id=6358, year=2003, month=9, destdir=".")
    met <- read.met(metFile)
    met <- oceSetData(met, "time", met[["time"]]+4*3600,
                     note="add 4h to local time to get UTC time")
    plot(met, which=3:4)

    ## End(Not run)

[Package oce version 1.0-1 Index]