Fit Point Process Model to Point Pattern on Linear Network
Fit a point process model to a point pattern dataset on a linear network
lppm(X, ...) ## S3 method for class 'formula' lppm(X, interaction=NULL, ..., data=NULL) ## S3 method for class 'lpp' lppm(X, ..., eps=NULL, nd=1000, random=FALSE)
X |
Either an object of class |
... |
Arguments passed to |
interaction |
An object of class |
data |
Optional. The values of spatial covariates (other than the Cartesian coordinates) required by the model. A list whose entries are images, functions, windows, tessellations or single numbers. |
eps |
Optional. Spacing between dummy points along each segment of the network. |
nd |
Optional. Total number of dummy points placed on
the network. Ignored if |
random |
Logical value indicating whether the grid of dummy points should be placed at a randomised starting position. |
This function fits a point process model to data that specify
a point pattern on a linear network. It is a counterpart of
the model-fitting function ppm
designed
to work with objects of class "lpp"
instead of "ppp"
.
The function lppm
is generic, with methods for
the classes formula
and lppp
.
In lppm.lpp
the first argument X
should be an object of class "lpp"
(created by the command lpp
) specifying a point pattern
on a linear network.
In lppm.formula
,
the first argument is a formula
in the R language
describing the spatial trend model to be fitted. It has the general form
pattern ~ trend
where the left hand side pattern
is usually
the name of a point pattern on a linear network
(object of class "lpp"
)
to which the model should be fitted, or an expression which evaluates
to such a point pattern;
and the right hand side trend
is an expression specifying the
spatial trend of the model.
Other arguments ...
are passed from lppm.formula
to lppm.lpp
and from lppm.lpp
to ppm
.
An object of class "lppm"
representing the fitted model.
There are methods for print
, predict
,
coef
and similar functions.
Adrian Baddeley Adrian.Baddeley@curtin.edu.au and Greg McSwiggan.
Ang, Q.W. (2010) Statistical methodology for events on a network. Master's thesis, School of Mathematics and Statistics, University of Western Australia.
Ang, Q.W., Baddeley, A. and Nair, G. (2012) Geometrically corrected second-order analysis of events on a linear network, with applications to ecology and criminology. Scandinavian Journal of Statistics 39, 591–617.
McSwiggan, G., Nair, M.G. and Baddeley, A. (2012) Fitting Poisson point process models to events on a linear network. Manuscript in preparation.
X <- runiflpp(15, simplenet) lppm(X ~1) lppm(X ~x) marks(X) <- factor(rep(letters[1:3], 5)) lppm(X ~ marks) lppm(X ~ marks * x)
Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.