| calif | California places |
| califcty | California counties |
| permuteinstrata | Randomize units within strata |
| pps1 | Select one unit with PPS |
| ppss | PPS systematic sampling |
| ppssstrat | Stratified PPS systematic sampling |
| ppswr | PPS sampling with replacement |
| sampford | Sampford's PPS sampling method |
| sampfordpi | Joint inclusion probabilities for Sampford's PPS sampling method |
| sizesok | Check that unit sizes are not too big |
| stratsrs | Stratified simple random sampling |
| stratumsizes | Compute size of each stratum |