# dataViewport: Create a Viewport with Scales based on Data

## Description

This is a convenience function for producing a viewport with
x- and/or y-scales based on numeric values passed to the function.

## Usage

dataViewport(xData = NULL, yData = NULL, xscale = NULL,
yscale = NULL, extension = 0.05, ...)

## Arguments

xData

A numeric vector of data.

yData

A numeric vector of data.

xscale

A numeric vector (length 2).

yscale

A numeric vector (length 2).

extension

A numeric. If length greater than 1, then
first value is used to extend the xscale and second value
is used to extend the yscale.

…

All other arguments will be passed to a call to
the `viewport()`

function.

## Value

A grid viewport object.

## Details

If `xscale`

is not specified then the values in `x`

are
used to generate an x-scale based on the range of `x`

, extended
by the proportion specified in `extension`

. Similarly for the
y-scale.