R: Augment data with information from a flexsurv model object

augment.flexsurvreg {flexsurv} | R Documentation

## Augment data with information from a flexsurv model object

### Description

Augment accepts a model object and a dataset and adds information about each observation in the dataset. Most commonly, this includes predicted values in the `.fitted` column, residuals in the `.resid` column, and standard errors for the fitted values in a `.se.fit` column. New columns always begin with a . prefix to avoid overwriting columns in the original dataset.

### Usage

    ## S3 method for class 'flexsurvreg'
    augment(
      x,
      data = NULL,
      newdata = NULL,
      type.predict = "response",
      type.residuals = "response",
      ...
    )

### Arguments

`x` | Output from `flexsurvreg` or `flexsurvspline`, representing a fitted survival model object.
`data` | A `data.frame` or `tibble` containing the original data that was used to produce the object `x`.
`newdata` | A `data.frame` or `tibble` containing all the original predictors used to create `x`. Defaults to `NULL`, indicating that nothing has been passed to `newdata`. If `newdata` is specified, the `data` argument will be ignored.
`type.predict` | Character indicating type of prediction to use. Passed to the `type` argument of the `predict` generic. Allowed arguments vary with model class, so be sure to read the `predict.my_class` documentation.
`type.residuals` | Character indicating type of residuals to use. Passed to the type argument of `residuals` generic. Allowed arguments vary with model class, so be sure to read the `residuals.my_class` documentation.
`...` | Additional arguments. Not currently used.

### Details

If neither of `data` or `newdata` are specified, then `model.frame(x)` will be used. It is worth noting that `model.frame(x)` will include a `Surv` object and not the original time-to-event variables used when fitting the `flexsurvreg` object. If the original data is desired, specify `data`.

### Value

A `tibble` containing `data` or `newdata` and possible additional columns:

- `.fitted` Fitted values of model

- `.se.fit` Standard errors of fitted values

- `.resid` Residuals (not present if `newdata` specified)

### Examples

    fit <- flexsurvreg(formula = Surv(futime, fustat) ~ age, data = ovarian, dist = "exp")
    augment(fit, data = ovarian)

[Package flexsurv version 2.0 Index]