## S3 method for class 'mppm':
vcov(object, ..., what="vcov", err="fatal")
"mppm"
)."vcov"
for the variance-covariance matrix,
"corr"
for the correlation matrix, or "fisher"
for the Fisher information matrix."fatal"
, "warn"
or "null"
.NA
or NULL
).vcov
.
The argument object
should be a fitted multiple point process
model (object of class "mppm"
) generated by mppm
.
The model must be a Poisson point process.
The variance-covariance matrix of the parameter estimates
is computed using asymptotic theory for maximum likelihood.
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}
.
These calculations are not available if the model is not Poisson,
or if it was computed using gam
. In such cases, 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
,
mppm
data(waterstriders)
fit <- mppm(Wat ~x, data=hyperframe(Wat=waterstriders))
vcov(fit)
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