# 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

 ```1 2 3 4 5``` ```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`)

`svyquantile`, `svyhist`, `plot.stepfun`

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22``` ```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

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.