# xDetails

##### Boundary of a grid grob

These generic functions are used to determine a location on the boundary of a grid grob.

- Keywords
- dplot

##### Usage

```
xDetails(x, theta)
yDetails(x, theta)
```

##### Arguments

- x
A grid grob.

- theta
A numeric angle, in degrees, measured anti-clockwise from the 3 o'clock

*or*one of the following character strings:`"north"`

,`"east"`

,`"west"`

,`"south"`

.

##### Details

The location on the grob boundary is determined by taking
a line from the centre of the grob at the angle `theta`

and intersecting it with the convex hull of the grob
(for the basic
grob primitives, the centre is
determined as half way between the minimum and maximum values
in x and y directions).

These functions are called in the calculation of
`"grobx"`

and `"groby"`

units as produced by
the `grobX`

and `grobY`

functions.
Methods should be written for classes derived from grob or gTree
where the boundary of the grob can be determined.

##### Value

A unit object.

##### See Also

*Documentation reproduced from package grid, version 3.4.1, License: Part of R 3.4.1*