# panel.contour

##### Panel Plots using Colour Image or Contour Lines

These functions can be passed to `pairs`

or
`coplot`

to determine what kind of plotting is done in each panel
of a multi-panel graphical display.

##### Usage

`panel.contour(x, y, ..., sigma = NULL)`panel.image(x, y, ..., sigma = NULL)

panel.histogram(x, ...)

##### Arguments

- x,y
- Coordinates of points in a scatterplot.
- ...
- Extra graphics arguments, passed to
`contour.im`

,`plot.im`

or`rect`

, respectively, to control th - sigma
- Bandwidth of kernel smoother, on a scale where $x$ and $y$ range between 0 and 1.

##### Details

These functions can serve as one of the arguments `panel`

,
`lower.panel`

, `upper.panel`

, `diag.panel`

passed to graphics commands like
`pairs`

or `coplot`

,
to determine what kind of plotting is done in each panel
of a multi-panel graphical display. In particular they work
with `pairs.im`

.

The functions `panel.contour`

and `panel.contour`

are suitable for the off-diagonal plots which involve
two datasets `x`

and `y`

.
They first rescale `x`

and `y`

to the unit square,
then apply kernel smoothing with bandwidth `sigma`

using `density.ppp`

.
Then `panel.contour`

draws a contour plot
while `panel.image`

draws a colour image.

The function `panel.histogram`

is suitable for the
diagonal plots which involve a single dataset `x`

.
It displays a histogram of the data.

##### Value

- Null.

##### See Also

##### Examples

```
with(bei.extra,
pairs(grad, elev,
panel = panel.contour,
diag.panel = panel.histogram))
```

*Documentation reproduced from package spatstat, version 1.42-2, License: GPL (>= 2)*