# vcov.coxph

##### Variance-covariance matrix

Extract and return the variance-covariance matrix.

- Keywords
- survival

##### Usage

```
# S3 method for coxph
vcov(object, complete=TRUE, ...)
# S3 method for survreg
vcov(object, complete=TRUE, ...)
```

##### Arguments

- object
a fitted model object

- complete
logical indicating if the full variance-covariance matrix should be returned. This has an effect only for an over-determined fit where some of the coefficients are undefined, and

`coef(object)`

contains corresponding NA values. If`complete=TRUE`

the returned matrix will have row/column for each coefficient, if FALSE it will contain rows/columns corresponding to the non-missing coefficients. The coef() function has a simpilar`complete`

argument.- …
additional arguments for method functions

##### Details

For the `coxph`

and `survreg`

functions the returned matrix
is a particular generalized inverse: the row and column corresponding
to any NA coefficients will be zero. This is a side effect of the
generalized cholesky decomposion used in the unerlying compuatation.

##### Value

a matrix

*Documentation reproduced from package survival, version 3.1-8, License: LGPL (>= 2)*