# plot.pppmatching

##### Plot a Point Matching

Plot an object of class `"pppmatching"`

which represents
a matching of two planar point patterns.

##### Usage

```
# S3 method for pppmatching
plot(x, addmatch = NULL, main = NULL, …, adjust = 1)
```

##### Arguments

- x
Point pattern matching object (class

`"pppmatching"`

) to be plotted.- addmatch
Optional. A matrix indicating additional pairs of points that should be matched. See Details.

- main
Main title for the plot.

- …
Additional arguments passed to other plot methods.

- adjust
Adjustment factor for the widths of line segments. A positive number.

##### Details

The object `x`

represents a matching found between
two point patterns `X`

and `Y`

. The matching may be
incomplete. See `pppmatching.object`

for further
description.

This function plots the matching by drawing the two point patterns
`X`

and `Y`

as red and blue dots respectively, and drawing
line segments between each pair of matched points. The width of the
line segments is proportional to the strength of matching. The
proportionality constant can be adjusted using the argument
`adjust`

.

Additional graphics arguments `…`

control the
plotting of the window (and are passed to `plot.owin`

)
and the plotting of the line segments
(and are passed to `plot.psp`

, `plot.linim`

and ultimately to the base graphics function
`polygon`

).

The argument `addmatch`

is for use mainly by developers to
study algorithms which update the matching.
If `addmatch`

is given, it should be a matrix with dimensions
`npoints(X) * npoints(Y)`

. If `addmatch[i,j] > 0`

then
a light grey line segment will be drawn between `X[i]`

and `Y[j`

.

##### Value

Null.

##### See Also

##### Examples

```
# NOT RUN {
X <- runifpoint(7)
Y <- runifpoint(7)
am <- r2dtable(1, rep(10,7), rep(10,7))[[1]]/10
m2 <- pppmatching(X, Y, am)
plot(m2, adjust=0.3)
# }
```

*Documentation reproduced from package spatstat, version 1.64-1, License: GPL (>= 2)*