svycdf: Cumulative Distribution Function

In survey: Analysis of Complex Survey Samples

Description

Estimates the population cumulative distribution function for specified variables. In contrast to svyquantile, this does not do any interpolation: the result is a right-continuous step function.

Usage

svycdf(formula, design, na.rm = TRUE,...)
## S3 method for class 'svycdf'
print(x,...)
## S3 method for class 'svycdf'
plot(x,xlab=NULL,...)

Arguments

formula	one-sided formula giving variables from the design object
design	survey design object
na.rm	remove missing data (case-wise deletion)?
...	other arguments to plot.stepfun
x	object of class svycdf
xlab	a vector of x-axis labels or NULL for the default labels

Value

An object of class svycdf, which is a list of step functions (of class stepfun)

See Also

svyquantile, svyhist, plot.stepfun

Examples

data(api)
dstrat <- svydesign(id = ~1, strata = ~stype, weights = ~pw, data = apistrat, 
    fpc = ~fpc)
cdf.est<-svycdf(~enroll+api00+api99, dstrat)
cdf.est
## function
cdf.est[[1]]
## evaluate the function
cdf.est[[1]](800)
cdf.est[[2]](800)

## compare to population and sample CDFs.
opar<-par(mfrow=c(2,1))
cdf.pop<-ecdf(apipop$enroll)
cdf.samp<-ecdf(apistrat$enroll)
plot(cdf.pop,main="Population vs sample", xlab="Enrollment")
lines(cdf.samp,col.points="red")

plot(cdf.pop, main="Population vs estimate", xlab="Enrollment")
lines(cdf.est[[1]],col.points="red")

par(opar)

Example output

Loading required package: grid
Loading required package: Matrix
Loading required package: survival

Attaching package: 'survey'

The following object is masked from 'package:graphics':

    dotchart

Weighted ECDFs: svycdf(~enroll + api00 + api99, dstrat)
Step function
Call: svycdf.default(formula = ~enroll, design = dstrat)
 x[1:187] =    119,    143,    153,  ...,   2552,   3156
188 plateau levels =      0, 0.0024378, 0.0095754,  ..., 0.99756,      1
[1] 0.8223603
[1] 0.8463626

survey documentation built on July 19, 2021, 9:06 a.m.