These functions set up various label placement strategies.

## Usage

```
label_placer_minmax(
placement = "tb",
rot_adjuster = angle_halfcircle_bottom(),
n = 2
)
label_placer_none()
label_placer_manual(breaks, x, y, theta)
label_placer_middle(rot_adjuster = angle_halfcircle_bottom())
```

## Arguments

- placement
String consisting of any combination of the letters "t", "r", "b", "l" indicating the placement of labels at the top, to the right, at the bottom, to the left of the isoline.

- rot_adjuster
Function that standardizes the rotation angles of the labels. See e.g.

`angle_halfcircle_bottom()`

.- n
Size of the point neighborhood over which the rotation angle should be calculated.

- breaks
Character vector specifying the isolines to be labeled, as in

`isolines_grob()`

.- x, y, theta
Numeric vectors specifying the x and y positions and angles (in radians) for each label corresponding to each break.