# Aalen-Johansen nonparametric estimates comparable to a fitted flexsurvmix model

Source:`R/summary.flexsurvmix.R`

`ajfit.Rd`

Given a fitted flexsurvmix model, return the Aalen-Johansen estimates of the
probability of occupying each state at a series of times covering the
observed data. State 1 represents not having experienced any of the
competing events, while state 2 and any further states correspond to having
experienced each of the competing events respectively. These estimates can
be compared with the fitted probabilities returned by
`p_flexsurvmix`

to check the fit of a `flexsurvmix`

model.

## Arguments

- x
Fitted model returned by

`flexsurvmix`

.- newdata
Data frame of alternative covariate values to check fit for. Only factor covariates are supported.

- tidy
If

`TRUE`

then a single tidy data frame is returned. Otherwise the function returns the object returned by`survfit`

, or a list of these objects if we are computing subset-specific estimates.

## Details

This is only supported for models with no covariates or models containing only factor covariates.

For models with factor covariates, the Aalen-Johansen estimates are computed
for the subsets of the data defined in `newdata`

. If `newdata`

is
not supplied, then this function returns state occupancy probabilities for
all possible combinations of the factor levels.

The Aalen-Johansen estimates are computed using
`survfit`

from the `survival`

package (Therneau
2020).