plot.survfit {survival} | R Documentation |

##
Plot method for `survfit`

objects

### Description

A plot of survival curves is produced, one curve for each strata.
The `log=T`

option does extra work to avoid log(0), and to try to create a
pleasing result. If there are zeros, they are plotted by default at
0.8 times the smallest non-zero value on the curve(s).

Curves are plotted in the same order as they are listed by `print`

(which gives a 1 line summary of each).
This will be the order in which `col`

, `lty`

, etc are used.

### Usage

```
## S3 method for class 'survfit'
plot(x, conf.int=, mark.time=FALSE,
pch=3, col=1, lty=1, lwd=1, cex=1, log=FALSE, xscale=1, yscale=1,
xlim, ylim, xmax, fun,
xlab="", ylab="", xaxs="r", conf.times, conf.cap=.005,
conf.offset=.012,
conf.type = c("log", "log-log", "plain", "logit", "arcsin"),
mark, noplot="(s0)", cumhaz=FALSE,
firstx, ymin, ...)
```

### Arguments

`x` |
an object of class |

`conf.int` |
determines whether pointwise confidence intervals will be plotted. The default is to do so if there is only 1 curve, i.e., no strata, using 95% confidence intervals Alternatively, this can be a numeric value giving the desired confidence level. |

`mark.time` |
controls the labeling of the curves. If set to |

`pch` |
vector of characters which will be used to label the curves.
The |

`col` |
a vector of integers specifying colors for each curve. The default value is 1. |

`lty` |
a vector of integers specifying line types for each curve. The default value is 1. |

`lwd` |
a vector of numeric values for line widths. The default value is 1. |

`cex` |
a numeric value specifying the size of the marks. This is not treated as a vector; all marks have the same size. |

`log` |
a logical value, if TRUE the y axis wll be on a log scale. Alternately, one of the standard character strings "x", "y", or "xy" can be given to specific logarithmic horizontal and/or vertical axes. |

`xscale` |
a numeric value used like |

`yscale` |
a numeric value used to multiply the labels on the y axis.
A value of 100, for instance, would be used to give a percent scale.
Only the labels are
changed, not the actual plot coordinates, so that adding a curve with
" |

`xlim` , `ylim` |
optional limits for the plotting region. |

`xmax` |
the maximum horizontal plot coordinate. This can be used to shrink
the range of a plot. It shortens the curve before plotting it, so
that unlike using the |

`fun` |
an arbitrary function defining a transformation of the survival
(or probability in state, or cumulative hazard) curves.
For example |

`xlab` |
label given to the x-axis. |

`ylab` |
label given to the y-axis. |

`xaxs` |
either |

`conf.times` |
optional vector of times at which to place a confidence bar on the curve(s). If present, these will be used instead of confidence bands. |

`conf.cap` |
width of the horizontal cap on top of the confidence bars; only used if conf.times is used. A value of 1 is the width of the plot region. |

`conf.offset` |
the offset for confidence bars, when there are multiple curves on the plot. A value of 1 is the width of the plot region. If this is a single number then each curve's bars are offset by this amount from the prior curve's bars, if it is a vector the values are used directly. |

`conf.type` |
One of |

`mark` |
a historical alias for |

`noplot` |
for multi-state models, curves with this label will not
be plotted. (Also see the |

`cumhaz` |
plot the cumulative hazard rather than the probability
in state or survival. Optionally, this can be a numeric vector
specifying which columns of the |

`ymin` |
this will normally be given as part of the |

`firstx` |
this will normally be given as part of the |

`...` |
other arguments that will be passed forward to the underlying plot method, such as xlab or ylab. |

### Details

If the object contains a cumulative hazard curve, then
`fun='cumhaz'`

will plot that curve, otherwise it will plot
-log(S) as an approximation. Theoretically, S =
`\exp(-\Lambda)`

where S is the survival and
`\Lambda`

is the cumulative hazard. The same relationship
holds for estimates of S and `\Lambda`

only in special cases,
but the approximation is often close.

When the `survfit`

function creates a multi-state survival curve
the resulting object also has class ‘survfitms’.
Competing risk curves are a common case.
In this situation the `fun`

argument is ignored.

When the `conf.times`

argument is used, the confidence bars are
offset by `conf.offset`

units to avoid overlap.
The bar on each curve are the confidence interval for the time point
at which the bar is drawn, i.e., different time points for each curve.
If curves are steep at that point, the visual impact can sometimes
substantially differ for positive and negative values of
`conf.offset`

.

### Value

a list with components `x`

and `y`

, containing the coordinates of the last point
on each of the curves (but not the confidence limits).
This may be useful for labeling.

### Note

In prior versions the behavior of `xscale`

and
`yscale`

differed: the first changed the scale both for the plot
and for all subsequent actions such as adding a legend, whereas `yscale`

affected only the axis label. This was normalized in version 2-36.4,
and both parameters now only affect the labeling.

In versions prior to approximately 2.36 a `survfit`

object did
not contain the cumulative hazard as a separate result, and the use of
fun="cumhaz" would plot the approximation -log(surv) to the cumulative
hazard. When cumulative hazards were added to the object, the
`cumhaz=TRUE`

argument to the plotting function was added.
In version 2.3-8 the use of fun="cumhaz" became a synonym for
`cumhaz=TRUE`

.

### See Also

`points.survfit`

,
`lines.survfit`

,
`par`

,
`survfit`

### Examples

```
leukemia.surv <- survfit(Surv(time, status) ~ x, data = aml)
plot(leukemia.surv, lty = 2:3)
legend(100, .9, c("Maintenance", "No Maintenance"), lty = 2:3)
title("Kaplan-Meier Curves\nfor AML Maintenance Study")
lsurv2 <- survfit(Surv(time, status) ~ x, aml, type='fleming')
plot(lsurv2, lty=2:3, fun="cumhaz",
xlab="Months", ylab="Cumulative Hazard")
```

*survival*version 3.6-4 Index]