| Type: | Package | 
| Title: | An Implementation of the Stratification Index | 
| Version: | 0.1 | 
| Description: | An implementation of the stratification index proposed by Zhou (2012) <doi:10.1177/0081175012452207>. The package provides two functions, srank, which returns stratum-specific information, including population share and average percentile rank; and strat, which returns the stratification index and its approximate standard error. When a grouping factor is specified, strat also provides a detailed decomposition of the overall stratification into between-group and within-group components. | 
| Depends: | R (≥ 3.3.1), | 
| Imports: | Hmisc (≥ 4.0-0), Rcpp, stats | 
| LinkingTo: | Rcpp, RcppArmadillo | 
| License: | GPL (≥ 3) | 
| LazyData: | TRUE | 
| RoxygenNote: | 5.0.1 | 
| Suggests: | testthat | 
| URL: | https://github.com/xiangzhou09/strat | 
| BugReports: | https://github.com/xiangzhou09/strat/issues | 
| NeedsCompilation: | yes | 
| Packaged: | 2016-11-22 17:44:43 UTC; xiz225 | 
| Author: | Xiang Zhou [aut, cre] | 
| Maintainer: | Xiang Zhou <xiang_zhou@fas.harvard.edu> | 
| Repository: | CRAN | 
| Date/Publication: | 2016-11-23 01:26:06 | 
A Subset of March CPS 2015 Sample
Description
A dataset containing income, big class, microclass, and education of 14,358 male respondents from March CPS 2015
Usage
cpsmarch2015
Format
A data frame with 14358 rows and 5 variables:
- income
- personal market income, in US dollars 
- big_class
- big class membership 
- micro_class
- microclass membership 
- education
- educational attainment 
- weight
- sampling weight given by CPS 
Print an object of class srank
Description
Print an object of class srank
Usage
## S3 method for class 'srank'
print(x, digits = 3, ...)
Arguments
| x | An object of class  | 
| digits | the number of significant digits to use when printing | 
| ... | further arguments passed to or from other methods | 
Print an object of class strat
Description
Print an object of class strat
Usage
## S3 method for class 'strat'
print(x, digits = 3, ...)
Arguments
| x | An object of class  | 
| digits | the number of significant digits to use when printing | 
| ... | further arguments passed to or from other methods | 
Ranking strata.
Description
Ranking strata according to the average percentile rank of members in each stratum.
Usage
srank(outcome, strata, weights = NULL, group = NULL)
Arguments
| outcome | A numeric vector of outcome. | 
| strata | A vector of  | 
| weights | An optional vector of weights. | 
| group | An optional grouping factor. | 
Value
An object of class srank. 
| raw | a data frame consisting of complete cases of all inputs. | 
| summary | a data frame of stratum-specific information, including name, population share, and average percentile rank. | 
Examples
strata_info <- with(cpsmarch2015, srank(income, big_class,
 weights = weight, group = education))
print(strata_info, digits = 3)
Stratification index.
Description
strat computes the stratification index proposed in Zhou (2012). When
group is specified, it also returns between-group and within-group
components of the overall stratification.
Usage
strat(outcome, strata, weights = NULL, ordered = FALSE, group = NULL)
Arguments
| outcome | A numeric vector of outcome. | 
| strata | A vector of  | 
| weights | An optional vector of weights. | 
| ordered | Logical. If  | 
| group | An optional grouping factor. If specified,  | 
Value
An object of class strat. 
| overall | a vector of two, giving computed stratification index and approximate standard error. | 
| strata_info | a data frame of stratum-specific information, including name, population share, and average percentile rank. | 
| decomposition | between-group and within-group components of the overall stratification. | 
| within_group | within-group indices of stratification by group. | 
References
Zhou, Xiang. 2012. "A Nonparametric Index of Stratification." Sociological Methodology, 42(1): 365-389.
Examples
s <- with(cpsmarch2015, strat(income, big_class,
 weights = weight, group = education))
print(s, digits = 4)
print(s$strata_info, digits = 4)
print(s$within_group, digits = 4)