R: Group Generic Functions

BasicFunctions {methods} | R Documentation

## Group Generic Functions

### Description

These are group generic functions. Methods defined for them will be used for any of the specific functions belonging to the particular group, provided no specific methods override.

These functions should never be called directly (a suitable error message will result if they are).

### Usage

    Arith(e1, e2)
    Compare(e1, e2)
    Ops(e1, e2)

    Math(x)
    Math2(x, digits)

    Summary(x, ..., na.rm = FALSE)

    Complex(z)

### Arguments

`e1, e2` | Arguments to the various binary operators.
`x` | The argument to the `Math` or `Summary` groups of functions.

### Details

The functions belonging to the various groups are as follows:

`Arith`
  `"+", "-", "*", "^", "%%", "%/%", "/"`
`Compare`
  `"==", ">", "<", "!=", "<=", ">="`
`Ops`
  `"Arith", "Compare"`
`Math`
  `"log", "sqrt", "log10", "cumprod", "abs", "acos", "acosh", "asin", "asinh", "atan", "atanh", "ceiling", "cos", "cosh", "cumsum", "exp", "floor", "gamma", "lgamma", "sin", "sinh", "tan", "tanh", "trunc"`
`Math2`
  `"round", "signif"`
`Summary`
  `"max", "min", "range", "prod", "sum", "any", "all"`
`Complex`
  `"Arg", "Conj", "Im", "Mod", "Re"`

All the functions in these groups (other than the group generics themselves) are basic functions in R. They are not by default generic functions, and many of them are defined as primitives, meaning that they do not have formal arguments. However, you can still define methods for them. The effect of doing so is to create a generic function with the appropriate arguments, in the environment where the method definition is to be stored. It all works more or less as you might expect, admittedly via a bit of trickery in the background.

### Author(s)

John Chambers

### References

The web page http://www.omegahat.org/RSMethods/index.html is the primary documentation.

The functions in this package emulate the facility for classes and methods described in Programming with Data, (John M. Chambers, Springer, 1998). See this book for further details and examples.

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