plot.Uhaz: Plot Functions for U-shaped Hazard Estimation

In npsurv: Nonparametric Survival Analysis

Description

Functions for plotting various functions in U-shaped hazard estimation

Usage

## S3 method for class 'Uhaz'
plot(x, ...)
## S3 method for class 'uh'
plot(x, data, fn=c("haz","grad","surv","den","chaz"), ...)
plothazuh(h, add=FALSE, col="darkblue", lty=1, xlim, ylim,
         lwd=2, pch=19, len=500, vert=FALSE, add.knots=TRUE,
         xlab="Time", ylab="Hazard", ...)
plotchazuh(h, add=FALSE, lwd=2, len=500, col="darkblue",
          pch=19, add.knots=TRUE, vert=FALSE, xlim, ylim, ...)
plotdenuh(h, add=FALSE, lty=1, lwd=2, col="darkblue",
         add.knots=TRUE, pch=19, ylim, len=500, vert=FALSE, ...)
plotsurvuh(h, add=FALSE, lty=1, lwd=2, len=500, vert=FALSE,
          col="darkblue", pch=19, add.knots=TRUE, xlim, ylim, ...)
plotgraduh(h, data, w=1, len=500, xlim, ylim, vert=TRUE,
          add=FALSE, xlab="Time", ylab="Gradient",
          col0="red3", col1="blue3", col2="green3", order=0, ...)

Arguments

x	an object of class Uhaz, i.e., an output of function Uhaz, or an object of class uh..
...	arguments for other graphical parameters (see par).
h	an object of class uh.
data	vector or matrix that stores observations, or an object of class icendata.
w	additional weights/multiplicities for the observations stored in data.
fn	function to be plotted. It can be = haz, for hazard function; = chaz, for cumulative hazard function; = den, for density function; = surv, for survival function; = gradient, for gradient functions.
xlim, ylim	numeric vectors of length 2, giving the x and y coordinates ranges.
xlab, ylab	x- or y-axis labels.
add	= TRUE, adds the curve to the existing plot; = FALSE, plots the curve in a new one.
col	color used for plotting the curve.
lty	line type for plotting the curve.
lwd	line width for plotting the curve.
len	number of points used to plot a curve.
add.knots	logical, indicating if knots are also plotted.
pch	point character/type for plotting knots.
vert	logical, indicating if grey vertical lines are plotted to show the interval that separates the two discrete measures.
col0	color for gradient function 0, i.e., for the hazard-constant part, or alpha.
col1	color for gradient function 1, i.e., for the hazard-decreasing part.
col2	color for gradient function 1, i.e., for the hazard-increasing part.
order	= 0, the gradient functions are plotted; = 1, their first derivatives are plotted; = 2, their second derivatives are plotted.

Details

plot.Uhaz and plot.uh are wrapper functions that can be used to invoke plot.hazuh, plot.chazuh, plot.survuh, plot.denuh or plot.graduh.

plothazuh plots a U-shaped hazard function.

plotchazuh plots a cumulative hazard function that has a U-shaped hazard function.

plotsurvuh plots the survival function that has a U-shaped hazard function.

plotdenuh plots the density function that has a U-shaped hazard function.

plotgraduh plots the gradient function that has a U-shaped hazard function.

A U-shaped hazard function is given by

h(t) = alpha + sum_{j=1}^k nu_j (tau_j - t)_+^p + sum_{j=1}^m mu_j (t - eta_j)_+^p,

where alpha, nu_j, mu_j ≥ 0, tau_1 < ... < tau_k <= eta_1 < ... < eta_m, and p >= 0.

Author(s)

Yong Wang <[e-mail]>

References

Wang, Y. and Fani, S. (2018). Nonparametric maximum likelihood computation of a U-shaped hazard function. Statistics and Computing, 28, 187-200.

See Also

icendata, uh, npsurv.

Examples

## Angina Pectoris Survival Data
data(ap)
plot(r<-Uhaz(ap))              # hazard function for a convex hazard
plot(r, fn="c")                # cumulative hazard function
plot(r, fn="s")                # survival function
plot(r, fn="d")                # density function
plot(r, ap, fn="g")            # gradient functions
plot(r, ap, fn="g", order=1)   # first derivatives of gradient functions
plot(r, ap, fn="g", order=2)   # second derivatives of gradient functions

## New Zealand Mortality in 2000
data(nzmort)
i = nzmort$ethnic == "maori"
x = nzmort[i,1:2]                            # Maori mortality
h = Uhaz(x[,1]+0.5, x[,2], deg=2)$h          # smooth U-shaped hazard
plot(h)                        # hazard function
plot(h, fn="d")                # density function
plot(h, fn="s")                # survival function

x2 = nzmort[!i,1:2]                          # Non-Maori mortality
h2 = Uhaz(x2[,1]+0.5, x2[,2], deg=2)$h
plot(h2, fn="s", add=TRUE, col="green3")

npsurv documentation built on Oct. 23, 2020, 5:43 p.m.