# Obtain variance-covariance matrix from WCE models

### Description

The `vcov`

method returns the variance-covariance matrix of the estimated regression coefficients from a WCE model.

### Usage

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### Arguments

`object` |
A |

`...` |
Optional; other parameters to be passed through to |

### Value

The function returns variance-covariance matrices with the estimated regression coefficients for the supplied WCE model object. The number of matrices returned is equivalent to the length of the `nknots`

vector (or one matrix, if `nknots`

is a scalar) passed to the `WCE`

function when fitting the model.

### Author(s)

Marie-Pierre Sylvestre

marie-pierre.sylvestre@umontreal.ca

### References

Sylvestre MP, Abrahamowicz M. Flexible modeling of the cumulative effects of time-dependent exposures on the hazard. Stat Med. 2009 Nov 30;28(27):3437-53.

### Examples

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