# Developer documentation: model for covariates on transition intensities

Source:`R/internals_doc.R`

`qcmodel.object.Rd`

A list representing the model for covariates on transition intensities

## Value

- npars
Number of covariate effect parameters. This is defined as the number of covariates on intensities (with factors expanded as contrasts) multiplied by the number of allowed transitions in the model.

Note if

`msm`

was called with`covariates`

set to a list of different covariates for different intensities, then this will include covariate effects that are implicitly defined as zero by this list. The information in`paramdata`

objects can be used to identify wich ones are fixed at zero.This also includes any

`timeperiod`

covariates in a time-inhomogeneous model defined by the`pci`

option to`msm`

.- ndpars
Number of distinct covariate effect parameters, as

`npars`

, but after any equality constraints have been applied.- ncovs
Number of covariates on intensities, with factors expanded as contrasts.

- constr
List of equality constraints on these covariate effects, as supplied in the

`constraint`

argument to`msm`

.- covlabels
Names / labels of these covariates in the model matrix (see

`model.matrix.msm`

).- inits
Initial values for these covariate effects, as a vector formed from the

`covinits`

list supplied to`msm`

.- covmeans
Means of these covariates in the data (excluding data not required to fit the model, such as observations with missing data in other elements or subjects' last observations). This includes means of 0/1 factor contrasts as well as continuous covariates (for historic reasons, which may not be sensible).