with.ssf
Evaluate Expression in a Spatially Sampled Function
Given a spatially sampled function, evaluate an expression involving the function values.
 Keywords
 manip, spatial, programming
Usage
apply.ssf(X, ...)
"with"(data, ...)
Arguments
 X, data

A spatially sampled function (object of class
"ssf"
).  ...

Arguments passed to
with.default
orapply
specifying what to compute.
Details
An object of class "ssf"
represents a
function (real or vectorvalued) that has been
sampled at a finite set of points.
It contains a data frame
which provides the function values
at the sample points.
In with.ssf
, the expression specified by ...
will be evaluated in this dataframe.
In apply.ssf
, the dataframe will be subjected to
the apply
operator using the additional arguments
...
.
If the result of evaluation
is a data frame with one row for each data point,
or a numeric vector with one entry for each data point,
then the result will be an object of class "ssf"
containing this information. Otherwise, the result will be
a numeric vector.
Value

An object of class
"ssf"
or a numeric vector.
See Also
Examples
a < ssf(cells, data.frame(d=nndist(cells), i=1:npoints(cells)))
with(a, i/d)