survival_curve: Compute a tidy Weibull survival curve

In simulab: Simulates a Wide Variety of Data Shapes, Sizes and Distributions

Compute a tidy Weibull survival curve

Description

Evaluates the simstudy Weibull curve of define_survival(), S(t) = exp(-exp(formula) * t^(1 / shape) / scale), at n survival probabilities spread evenly from 1 - 1 / n down to 1 / n, inverting it for the matching times. The points are therefore equally spaced in survival probability, not in time.

Usage

survival_curve(formula, shape, scale = 1, n = 100L, time_limits = NULL)

Arguments

formula	Intercept of the linear predictor on the log scale. A single finite number. exp(formula) multiplies the cumulative hazard, and equals the hazard only when shape and scale are both 1.
shape	Positive Weibull shape in the simstudy parameterization, the exponent applied to the transformed time. A single positive number.
scale	Positive Weibull scale, dividing the cumulative hazard. A single positive number, defaulting to 1.
n	Number of curve points. A single whole number of at least 2, defaulting to 100.
time_limits	Optional inclusive time range, as an increasing non-negative numeric vector of length 2, that the curve is restricted to. Defaults to NULL, the whole curve. Points outside the range are dropped, so fewer than n rows are returned.

Value

A base data.frame with one row per retained curve point, in increasing time order, and columns time and survival.

Examples

curve <- survival_curve(formula = -8, shape = 0.3, n = 10)
head(curve)

simulab documentation built on Oct. 15, 2026, 5:08 p.m.