optmatch (version 0.2-2)

stratumStructure: Return structure of matched sets

Description

Tabulate treatment:control ratios occurring in matched sets, and the frequency of their occurrence.

Usage

stratumStructure(stratum,trtgrp=NULL)

Arguments

stratum

Matched strata, as returned by fullmatch or pairmatch

trtgrp

Dummy variable for treatment group membership. (Not required if stratum is an optmatch object, as returned by fullmatch or pairmatch.)

Value

• A table showing frequency of occurrence of those treatment:control ratios that occur.

See Also

matched, fullmatch

Examples

plantdist <- matrix(nrow=7, ncol=19,byrow=TRUE,data=c(
28, 0, 3,22,14,30,17,28,26,28,20,22,23,26,21,18,34,40,28,
24, 3, 0,22,10,27,14,26,24,24,16,19,20,23,18,16,31,37,25,
10,18,14,18, 4,12, 6,11, 9,10,14,12, 6,14,22,10,16,22,28,
 7,28,24, 8,14, 2,10, 6,12, 0,24,22, 4,24,32,20,18,16,38,
17,20,16,32,18,26,20,18,12,24, 0, 2,20, 6, 8, 4,14,20,14,
20,31,28,35,20,29,22,20,14,26,12, 9,22, 5,15,12, 9,11,12,
14,32,29,30,18,24,17,16,10,22,12,10,17, 6,16,14, 4, 8,17),
dimnames=list(c("A","B","C","D","E","F","G"),
c("H","I","J","K","L","M","N","O","P","Q","R",
"S","T","U","V","W","X","Y","Z")))

plantsfm <- fullmatch(plantdist) # A full match with unrestricted
                                 # treatment-control balance
plantsfm1 <- fullmatch(plantdist,min.controls=2, max.controls=3)

stratumStructure(plantsfm)
stratumStructure(plantsfm1)