R: Class to Store Bremen-formatted Data

bremen-class {oce} | R Documentation

## Class to Store Bremen-formatted Data

### Description

This class is for data stored in a format used at Bremen. It is somewhat similar to the odf, in the sense that it does not apply just to a particular instrument. Although some functions are provided for dealing with these data (see “Details”), the most common action is to read the data with `read.bremen()`, and then to coerce the object to another storage class (e.g. using `as.ctd()` for CTD-style data) so that specialized functions can be used thereafter.

### Slots

`data`

  As with all `oce` objects, the `data` slot for `bremen` objects is a list containing the main data for the object.

`metadata`

  As with all `oce` objects, the `metadata` slot for `bremen` objects is a list containing information about the `data` or about the object itself.

`processingLog`

  As with all `oce` objects, the `processingLog` slot for `bremen` objects is a list with entries describing the creation and evolution of the object. The contents are updated by various `oce` functions to keep a record of processing steps. Object summaries and `processingLogShow()` both display the log.

### Modifying slot contents

Although the `[[<-` operator may permit modification of the contents of bremen objects (see `[[<-,bremen-method`), it is better to use `oceSetData()` and `oceSetMetadata()`, because those functions save an entry in the `processingLog` that describes the change.

### Retrieving slot contents

The full contents of the `data` and `metadata` slots of a bremen object may be retrieved in the standard R way using `slot()`. For example `slot(o,"data")` returns the `data` slot of an object named `o`, and similarly `slot(o,"metadata")` returns the `metadata` slot.

The slots may also be obtained with the `[[,bremen-method` operator, as e.g. `o[["data"]]` and `o[["metadata"]]`, respectively.

The `[[,bremen-method` operator can also be used to retrieve items from within the `data` and `metadata` slots. For example, `o[["temperature"]]` can be used to retrieve temperature from an object containing that quantity. The rule is that a named quantity is sought first within the object's `metadata` slot, with the `data` slot being checked only if `metadata` does not contain the item. This `[[` method can also be used to get certain derived quantities, if the object contains sufficient information to calculate them. For example, an object that holds (practical) salinity, temperature and pressure, along with longitude and latitude, has sufficient information to compute Absolute Salinity, and so `o[["SA"]]` will yield the calculated Absolute Salinity.

It is also possible to find items more directly, using `oceGetData()` and `oceGetMetadata()`, but neither of these functions can retrieve derived items.

### Author(s)

Dan Kelley

### See Also

Other classes provided by oce: `adp-class`, `adv-class`, `argo-class`, `cm-class`, `coastline-class`, `ctd-class`, `lisst-class`, `lobo-class`, `met-class`, `oce-class`, `odf-class`, `rsk-class`, `sealevel-class`, `section-class`, `topo-class`, `windrose-class`, `xbt-class`

Other things related to bremen data: `[[,bremen-method`, `[[<-,bremen-method`, `plot,bremen-method`, `read.bremen()`, `summary,bremen-method`

[Package oce version 1.7-2 Index]