Stores the numerator, denominator, and value of a ratio as a single object.

`rat(ratio, numerator, denominator, check = TRUE)`

An object equivalent to the object `ratio`

except that it also belongs to the class `"rat"`

and has additional attributes `numerator`

and `denominator`

.

- ratio,numerator,denominator
Three objects belonging to the same class.

- check
Logical. Whether to check that the objects are

`compatible`

.

Adrian Baddeley Adrian.Baddeley@curtin.edu.au and Rolf Turner r.turner@auckland.ac.nz.

The class `"rat"`

is a simple mechanism for keeping track of
the numerator and denominator when calculating a ratio. Its main
purpose is simply to signal that the object is a ratio.

The function `rat`

creates an object of class `"rat"`

given the numerator, the denominator and the ratio.
No calculation is performed;
the three objects are simply stored together.

The arguments `ratio`

, `numerator`

, `denominator`

can be objects of any kind. They should belong to the same class.
It is assumed that the relationship
$$
\mbox{ratio} = \frac{\mbox{numerator}}{\mbox{denominator}}
$$
holds in some version of arithmetic. However, no calculation is
performed.

By default the algorithm checks
whether the three arguments `ratio`

, `numerator`

,
`denominator`

are compatible objects, according to
`compatible`

.

The result is equivalent to `ratio`

except for the
addition of extra information.

`compatible`

,
`pool`