.nncross {groupedHyperframe} | R Documentation |
Alternative Interface of nncross.ppp
Description
An alternative interface of function nncross.ppp.
Usage
.nncross(X, i, j, ...)
Arguments
X |
see Details |
i , j |
character or integer scalars. See functions Gcross, etc. for more details |
... |
additional parameters of nncross.ppp |
Details
Function .nncross()
creates an interface similar to
functions Gcross, etc.,
which takes an is.multitype ppp.object
and two mark values i
and j
,
then calls the workhorse function
nncross.ppp with parameter what = 'dist'
.
If mark values i
and j
does not exist in the ppp.object,
a NULL
value will be returned.
Value
Function .nncross()
returns
a numeric vector
if i
and j
are valid mark values of ppp.object X
;
otherwise returns a NULL
value.
Examples
library(spatstat.data)
library(spatstat.geom)
(xs = split.ppp(amacrine))
(a1 = nncross(X = xs$off, Y = xs$on, what = 'dist'))
a2 = .nncross(amacrine, i = 'off', j = 'on')
a3 = .nncross(amacrine, i = 1L, j = 2L)
stopifnot(identical(a1, a2), identical(a1, a3))
.nncross(amacrine, i = 'a', j = 'b') # exception handling
[Package groupedHyperframe version 0.2.4 Index]