For a multitype point pattern on a linear network, estimate the multitype \(K\) function which counts the expected number of points of type \(j\) within a given distance of a point of type \(i\).
linearKcross(X, i, j, r=NULL, …, correction="Ang")The observed point pattern,
from which an estimate of the cross type \(K\) function
\(K_{ij}(r)\) will be computed.
An object of class "lpp" which
must be a multitype point pattern (a marked point pattern
whose marks are a factor).
Number or character string identifying the type (mark value)
of the points in X from which distances are measured.
Defaults to the first level of marks(X).
Number or character string identifying the type (mark value)
of the points in X to which distances are measured.
Defaults to the second level of marks(X).
numeric vector. The values of the argument \(r\) at which the \(K\)-function \(K_{ij}(r)\) should be evaluated. There is a sensible default. First-time users are strongly advised not to specify this argument. See below for important conditions on \(r\).
Geometry correction.
Either "none" or "Ang". See Details.
Ignored.
An object of class "fv" (see fv.object).
The arguments i and j are interpreted as
levels of the factor marks(X). Beware of the usual
trap with factors: numerical values are not
interpreted in the same way as character values.
This is a counterpart of the function Kcross
for a point pattern on a linear network (object of class "lpp").
The arguments i and j will be interpreted as
levels of the factor marks(X).
If i and j are missing, they default to the first
and second level of the marks factor, respectively.
The argument r is the vector of values for the
distance \(r\) at which \(K_{ij}(r)\) should be evaluated.
The values of \(r\) must be increasing nonnegative numbers
and the maximum \(r\) value must not exceed the radius of the
largest disc contained in the window.
Baddeley, A, Jammalamadaka, A. and Nair, G. (to appear) Multitype point process analysis of spines on the dendrite network of a neuron. Applied Statistics (Journal of the Royal Statistical Society, Series C), In press.
# NOT RUN {
data(chicago)
K <- linearKcross(chicago, "assault", "robbery")
# }
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