R: Look Within the First Element of a List for Replacement...

lookWithin {oce} | R Documentation

## Look Within the First Element of a List for Replacement Values

### Description

Look Within the First Element of a List for Replacement Values

### Usage

    lookWithin(list)

### Arguments

`list` | A list of elements, typically arguments that will be used in sw functions.

### Details

This is a helper function used by various seawater functions. It is used for a call like `swRho(ctd)`, in which the first argument, which is normally `salinity` may be an object that contains salinity plus the other items that `swRho` expects to see as arguments. This shorthand is very helpful in calls to the suite of `sw` functions. If this first argument is an object of this sort, then the other arguments are ignored except for two special cases:

- an item named `eos` is copied directly from `list`

- if the object stores `temperature` defined with the IPTS-68 scale, then `T90fromT68` is used to convert to the ITS-90 scale, because this is what is expected in most seawater functions. (For example, the RMS difference between these temperature variants is 0.002C for the `ctd` dataset.)

### Value

A list with elements of the same names but possibly filled in from the first element.

[Package oce version 0.9-20 Index]