# plot.leverage.ppm

##### Plot Leverage Function

Generate a pixel image plot, or a perspective plot,
of a leverage function that has been computed by `leverage.ppm`

.

##### Usage

```
# S3 method for leverage.ppm
plot(x, …, showcut=TRUE, col.cut=par("fg"),
multiplot=TRUE)
``` # S3 method for leverage.ppm
persp(x, …, main)

##### Arguments

- x
Leverage measure (object of class

`"leverage.ppm"`

) computed by`leverage.ppm`

.- …
Arguments passed to

`plot.im`

or`contour.im`

controlling the plot.- showcut
Logical. If

`TRUE`

, a contour line is plotted at the level equal to the theoretical mean of the leverage.- col.cut
Optional colour for the contour line.

- multiplot
Logical value indicating whether it is permissible to display several plot panels.

- main
Optional main title.

##### Details

These functions are the `plot`

and `persp`

methods
for objects of class `"leverage.ppm"`

.
Such objects are computed by the command `leverage.ppm`

.

The `plot`

method displays the leverage function
as a colour pixel image using `plot.im`

,
and draws a single contour line at the mean leverage value
using `contour.im`

.
Use the argument `clipwin`

to restrict the plot to a subset
of the full data.

The `persp`

method displays the leverage function as a surface
in perspective view, using `persp.im`

.

##### Value

##### References

Baddeley, A., Chang, Y.M. and Song, Y. (2013)
Leverage and influence diagnostics for spatial point process models.
*Scandinavian Journal of Statistics* **40**, 86--104.

##### See Also

##### Examples

```
# NOT RUN {
X <- rpoispp(function(x,y) { exp(3+3*x) })
fit <- ppm(X ~x+y)
lef <- leverage(fit)
plot(lef)
persp(lef)
# }
```

*Documentation reproduced from package spatstat, version 1.49-0, License: GPL (>= 2)*