R: Edit an Oce Object

oceEdit {oce} | R Documentation

## Edit an Oce Object

### Description

Edit an element of an oce object, inserting a note in the processing log of the returned object.

### Usage

    oceEdit(x, item, value, action, reason = "", person = "",
      debug = getOption("oceDebug"))

### Arguments

`x` | an `oce` object. The exact action of `oceEdit` depends on the `class` of `x`.
`item` | if supplied, a character string naming an item in the object's `metadata` or `data` slot, the former being checked first. An exception is if `item` starts with `"data@"` or `"metadata@"`, in which case the named slot is updated with a changed value of the contents of `item` after the `@` character.
`value` | new value for `item`, if both supplied.
`action` | optional character string containing R code to carry out some action on the object.
`reason` | character string giving the reason for the change.
`person` | character string giving the name of person making the change.
`debug` | an integer that specifies a level of debugging, with 0 or less indicating no debugging, and 1 or more indicating debugging.

### Details

There are several ways to use this function.

- Case 1. If both an `item` and `value` are supplied, then either the object's metadata or data slot may be altered. There are two ways in which this can be done.

  - Case 1A. If the `item` string does not contain an `@` character, then the `metadata` slot is examined for an entry named `item`, and that is modified if so. Alternatively, if `item` is found in `metadata`, then that value is modified. However, if `item` is not found in either `metadata` or `data`, then an error is reported (see 1B for how to add something that does not yet exist).

  - Case 1B. If the `item` string contains the `@` character, then the text to the left of that character must be either `"metadata"` or `"data"`, and it names the slot in which the change is done. In contrast with case 1A, this will create a new item, if it is not already in existence.

- Case 2. If `item` and `value` are not supplied, then `action` must be supplied. This is a character string specifying some action to be performed on the object, e.g. a manipulation of a column. The action must refer to the object as `x`; see Examples.

In any case, a log entry is stored in the object, to document the change. Indeed, this is the main benefit to using this function, instead of altering the object directly. The log entry will be most useful if it contains a brief note on the `reason` for the change, and the name of the `person` doing the work.

### Value

An object of `class` `"oce"`, altered appropriately, and with a log item indicating the nature of the alteration.

### Author(s)

Dan Kelley

### Examples

    library(oce)
    data(ctd)
    ctd2 <- oceEdit(ctd, item="latitude", value=47.8879,
                   reason="illustration", person="Dan Kelley")
    ctd3 <- oceEdit(ctd,action="x@data$pressure<-x@data$pressure-1")

[Package oce version 1.0-1 Index]