"vcov"(object, ..., what="vcov", err="fatal")
"mppm"
).
vcov.ppm
.
"vcov"
for the variance-covariance matrix,
"corr"
for the correlation matrix, and "fisher"
for the Fisher information matrix.
"fatal"
, "warn"
or "null"
.
NA
or NULL
).
vcov.ppm
for suggestions on how to handle this.vcov
.
The argument object
should be a fitted multiple point process
model (object of class "mppm"
) generated by mppm
.
The variance-covariance matrix of the parameter estimates
is computed using asymptotic theory for maximum likelihood
(for Poisson processes) or estimating equations (for other Gibbs models).
If what="vcov"
(the default), the variance-covariance matrix
is returned.
If what="corr"
, the variance-covariance matrix is normalised
to yield a correlation matrix, and this is returned.
If what="fisher"
, the Fisher information matrix is returned instead. In all three cases, the rows and columns of the matrix correspond
to the parameters (coefficients) in the same order as in
coef{model}
.
If errors or numerical problems occur, the
argument err
determines what will happen. If
err="fatal"
an error will occur. If err="warn"
a warning will be issued and NA
will be returned.
If err="null"
, no warning is issued, but NULL
is returned.
vcov
, vcov.ppm
,
mppm
fit <- mppm(Wat ~x, data=hyperframe(Wat=waterstriders))
vcov(fit)
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