plot.NPHpwr {nphPower}

Graphical Display of Design Parameters in Sample Size Calculation

Description

Displays graphs of survival, hazards, drop-out and censor over time as specified in the calculation.

Usage

## S3 method for class 'NPHpwr'
plot(x, type = c("hazard", "survival", "dropout", "event", "censor"), ...)

Arguments

x

object of the pwr2n.NPH function

type

a vector of string, specifying the graphs to display. The options include "hazard", "survival", "dropout", "event", and "censor". If type is not provided, all the available graphs are generated.

...

additional graphical arguments passed to the plot function

Details

The type argument provides five options to visualize the trial in design. Option survival shows the survival probabilities of treatment and control group over time. Option hazard provides the hazard rates and hazard ratio over time. Option dropout shows the proportion of drop-out subjects across the trial duration. Option censor shows the proportion of censored subjects over time.

Value

plots are produced on the current graphics device

See Also

pwr2n.NPH

Examples

 # generate weight function
 wlr <- gen.wgt(method = "LR" )
 t_enrl <- 12; t_fup <- 18; lmd0 <- log(2)/12
 # delayed treatment effects, the crossign point is at 6.
 f_hr_delay <- function(x){(x<=6)+(x>6)*0.75}
 f_haz0 <- function(x){lmd0*x^0}
 snph1 <- pwr2n.NPH(entry = t_enrl, fup = t_fup, Wlist = wlr,
                    k = 100, ratio = 2, CtrlHaz = f_haz0,
                    hazR = f_hr_delay)
 # display the hazards plot only
 plot(snph1, type="hazard")
 # display all plots
 plot(snph1)