agreg.fit {survival} | R Documentation |

## Cox model fitting functions

### Description

These are the the functions called by coxph that do the actual
computation.
In certain situations, e.g. a simulation, it may be advantageous to
call these directly rather than the usual `coxph`

call using
a model formula.

### Usage

```
agreg.fit(x, y, strata, offset, init, control, weights, method,
rownames, resid=TRUE, nocenter=NULL)
coxph.fit(x, y, strata, offset, init, control, weights, method,
rownames, resid=TRUE, nocenter=NULL)
```

### Arguments

`x` |
Matix of predictors. This should |

`y` |
a |

`strata` |
a vector containing the stratification, or NULL |

`offset` |
optional offset vector |

`init` |
initial values for the coefficients |

`control` |
the result of a call to |

`weights` |
optional vector of weights |

`method` |
method for handling ties, one of "breslow" or "efron" |

`rownames` |
this is only needed for a NULL model, in which case it contains the rownames (if any) of the original data. |

`resid` |
compute and return residuals. |

`nocenter` |
an optional list of values. Any column of the X matrix whose values lie strictly within that set will not be recentered. Note that the coxph function has (-1, 0, 1) as the default. |

### Details

This routine does no checking that arguments are the proper length or type. Only use it if you know what you are doing!

The `resid`

and `concordance`

arguments will save some compute
time for calling routines that only need the likelihood,
the generation of a permutation distribution for instance.

### Value

a list containing results of the fit

### Author(s)

Terry Therneau

### See Also

*survival*version 3.6-4 Index]