# Wrappers for specifying PPS designs

### Description

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.

### Usage

1 2 |

### Arguments

`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 |

`jointprob` |
Matrix of pairwise sampling probabilities for the sampled individuals |

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

### Value

An object of class `HR`

or `ppsmat`

, suitable for supplying as the `pps`

argument to `svydesign`

.

### See Also

election for examples of PPS designs

### Examples

1 | ```
HR(0.1)
``` |