`HR.Rd`

The Horvitz-Thompson estimator and the Hartley-Rao approximation require information in addition to the sampling probabilities for sampled individuals. These functions allow this information to be supplied.

```
HR(psum=NULL, strata = NULL)
ppsmat(jointprob, tolerance = 1e-04)
ppscov(probcov, weighted=FALSE)
```

- psum
The sum of squared sampling probabilities for the population, divided by the sample size, as a single number or as a vector for stratified sampling

- strata
Stratum labels, of the same length as

`psum`

, if`psum`

is a vector- jointprob
Matrix of pairwise sampling probabilities for the sampled individuals

- tolerance
Tolerance for deciding that the covariance of sampling indicators is zero

- probcov
Covariance of the sampling indicators (often written 'Delta'), or weighted covariance if

`weighted=TRUE`

- weighted
If

`TRUE`

, the`probcov`

argument is the covariance divided by pairwise sampling probabilities

An object of class `HR`

,`ppsmat`

, `ppsdelta`

, or `ppsdcheck`

suitable for supplying as the `pps`

argument to `svydesign`

.

election for examples of PPS designs

```
HR(0.1)
#> $pbar
#> $pbar[[1]]
#> [1] 0.1
#>
#>
#> $strata
#> $strata[[1]]
#> [1] 1
#>
#>
#> $call
#> HR(0.1)
#>
#> attr(,"class")
#> [1] "HR"
```