levels shows levels for variables in data frame, relevel relevels a factor in data.frame
drelevel(
data,
y = NULL,
x = NULL,
ref = NULL,
newlevels = NULL,
regex = mets.options()$regex,
sep = NULL,
overwrite = FALSE,
...
)if x is formula or names for data frame then data frame is needed.
name of variable, or fomula, or names of variables on data frame.
name of variable, or fomula, or names of variables on data frame.
new reference variable
to combine levels of factor in data frame
for regular expressions.
seperator for naming of cut names.
to overwrite variable
Optional additional arguments
data(mena)
dstr(mena)
#> 'data.frame': 2000 obs. of 7 variables:
#> $ cohort : Factor w/ 4 levels "[1973,1975]",..: 1 1 1 1 1 1 1 1 1 1 ...
#> $ agemena : num 13.8 12.7 12.4 13.1 13.5 ...
#> $ status : int 1 1 1 1 1 1 1 1 1 1 ...
#> $ zyg : Factor w/ 2 levels "MZ","DZ": 2 2 1 1 1 1 1 1 1 1 ...
#> $ twinnum : int 2 1 2 1 2 1 2 1 2 1 ...
#> $ id : num 1 1 2 2 3 3 4 4 5 5 ...
#> $ mothermena: num 13.5 13.5 12.5 12.5 14.7 ...
#> Warning: Calling 'structure(NULL, *)' is deprecated, as NULL cannot have attributes.
#> Consider 'structure(list(), *)' instead.
dfactor(mena) <- ~twinnum
dnumeric(mena) <- ~twinnum.f
dstr(mena)
#> 'data.frame': 2000 obs. of 9 variables:
#> $ cohort : Factor w/ 4 levels "[1973,1975]",..: 1 1 1 1 1 1 1 1 1 1 ...
#> $ agemena : num 13.8 12.7 12.4 13.1 13.5 ...
#> $ status : int 1 1 1 1 1 1 1 1 1 1 ...
#> $ zyg : Factor w/ 2 levels "MZ","DZ": 2 2 1 1 1 1 1 1 1 1 ...
#> $ twinnum : int 2 1 2 1 2 1 2 1 2 1 ...
#> $ id : num 1 1 2 2 3 3 4 4 5 5 ...
#> $ mothermena : num 13.5 13.5 12.5 12.5 14.7 ...
#> $ twinnum.f : Factor w/ 2 levels "1","2": 2 1 2 1 2 1 2 1 2 1 ...
#> $ twinnum.f.n: num 2 1 2 1 2 1 2 1 2 1 ...
#> Warning: Calling 'structure(NULL, *)' is deprecated, as NULL cannot have attributes.
#> Consider 'structure(list(), *)' instead.
mena2 <- drelevel(mena,"cohort",ref="(1980,1982]")
mena2 <- drelevel(mena,~cohort,ref="(1980,1982]")
mena2 <- drelevel(mena,cohortII~cohort,ref="(1980,1982]")
dlevels(mena)
#> cohort #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> twinnum.f #levels=:2
#> [1] "1" "2"
#> -----------------------------------------
dlevels(mena2)
#> cohort #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> twinnum.f #levels=:2
#> [1] "1" "2"
#> -----------------------------------------
#> cohortII #levels=:4
#> [1] "(1980,1982]" "[1973,1975]" "(1975,1977]" "(1977,1980]"
#> -----------------------------------------
drelevel(mena,ref="(1975,1977]") <- ~cohort
drelevel(mena,ref="(1980,1982]") <- ~cohort
dlevels(mena,"coh*")
#> cohort #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cohort.(1975,1977] #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cohort.(1980,1982] #levels=:4
#> [1] "(1980,1982]" "[1973,1975]" "(1975,1977]" "(1977,1980]"
#> -----------------------------------------
dtable(mena,"coh*",level=1)
#>
#> cohort
#> [1973,1975] (1975,1977] (1977,1980] (1980,1982]
#> 710 412 540 338
#>
#> cohort.(1975,1977]
#> (1975,1977] [1973,1975] (1977,1980] (1980,1982]
#> 412 710 540 338
#>
#> cohort.(1980,1982]
#> (1980,1982] [1973,1975] (1975,1977] (1977,1980]
#> 338 710 412 540
#>
### level 1 of zyg as baseline for new variable
drelevel(mena,ref=1) <- ~zyg
drelevel(mena,ref=c("DZ","[1973,1975]")) <- ~ zyg+cohort
drelevel(mena,ref=c("DZ","[1973,1975]")) <- zygdz+cohort.early~ zyg+cohort
### level 2 of zyg and cohort as baseline for new variables
drelevel(mena,ref=2) <- ~ zyg+cohort
dlevels(mena)
#> cohort #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> twinnum.f #levels=:2
#> [1] "1" "2"
#> -----------------------------------------
#> cohort.(1975,1977] #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cohort.(1980,1982] #levels=:4
#> [1] "(1980,1982]" "[1973,1975]" "(1975,1977]" "(1977,1980]"
#> -----------------------------------------
#> zyg.1 #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> zyg.DZ #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.[1973,1975] #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zygdz #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.early #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg.2 #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.2 #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
##################### combining factor levels with newlevels argument
dcut(mena,labels=c("I","II","III","IV")) <- cat4~agemena
dlevels(drelevel(mena,~cat4,newlevels=1:3))
#> cohort #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> twinnum.f #levels=:2
#> [1] "1" "2"
#> -----------------------------------------
#> cohort.(1975,1977] #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cohort.(1980,1982] #levels=:4
#> [1] "(1980,1982]" "[1973,1975]" "(1975,1977]" "(1977,1980]"
#> -----------------------------------------
#> zyg.1 #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> zyg.DZ #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.[1973,1975] #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zygdz #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.early #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg.2 #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.2 #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cat4 #levels=:4
#> [1] "I" "II" "III" "IV"
#> -----------------------------------------
#> cat4.1:3 #levels=:2
#> [1] "I-III" "IV"
#> -----------------------------------------
dlevels(drelevel(mena,ncat4~cat4,newlevels=3:2))
#> cohort #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> twinnum.f #levels=:2
#> [1] "1" "2"
#> -----------------------------------------
#> cohort.(1975,1977] #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cohort.(1980,1982] #levels=:4
#> [1] "(1980,1982]" "[1973,1975]" "(1975,1977]" "(1977,1980]"
#> -----------------------------------------
#> zyg.1 #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> zyg.DZ #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.[1973,1975] #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zygdz #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.early #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg.2 #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.2 #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cat4 #levels=:4
#> [1] "I" "II" "III" "IV"
#> -----------------------------------------
#> ncat4 #levels=:3
#> [1] "III-II" "I" "IV"
#> -----------------------------------------
drelevel(mena,newlevels=3:2) <- ncat4~cat4
dlevels(mena)
#> cohort #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> twinnum.f #levels=:2
#> [1] "1" "2"
#> -----------------------------------------
#> cohort.(1975,1977] #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cohort.(1980,1982] #levels=:4
#> [1] "(1980,1982]" "[1973,1975]" "(1975,1977]" "(1977,1980]"
#> -----------------------------------------
#> zyg.1 #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> zyg.DZ #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.[1973,1975] #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zygdz #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.early #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg.2 #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.2 #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cat4 #levels=:4
#> [1] "I" "II" "III" "IV"
#> -----------------------------------------
#> ncat4 #levels=:3
#> [1] "III-II" "I" "IV"
#> -----------------------------------------
dlevels(drelevel(mena,nca4~cat4,newlevels=list(c(1,4),2:3)))
#> cohort #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> twinnum.f #levels=:2
#> [1] "1" "2"
#> -----------------------------------------
#> cohort.(1975,1977] #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cohort.(1980,1982] #levels=:4
#> [1] "(1980,1982]" "[1973,1975]" "(1975,1977]" "(1977,1980]"
#> -----------------------------------------
#> zyg.1 #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> zyg.DZ #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.[1973,1975] #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zygdz #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.early #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg.2 #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.2 #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cat4 #levels=:4
#> [1] "I" "II" "III" "IV"
#> -----------------------------------------
#> ncat4 #levels=:3
#> [1] "III-II" "I" "IV"
#> -----------------------------------------
#> nca4 #levels=:2
#> [1] "I-IV" "II-III"
#> -----------------------------------------
drelevel(mena,newlevels=list(c(1,4),2:3)) <- nca4..2 ~ cat4
dlevels(mena)
#> cohort #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> twinnum.f #levels=:2
#> [1] "1" "2"
#> -----------------------------------------
#> cohort.(1975,1977] #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cohort.(1980,1982] #levels=:4
#> [1] "(1980,1982]" "[1973,1975]" "(1975,1977]" "(1977,1980]"
#> -----------------------------------------
#> zyg.1 #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> zyg.DZ #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.[1973,1975] #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zygdz #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.early #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg.2 #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.2 #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cat4 #levels=:4
#> [1] "I" "II" "III" "IV"
#> -----------------------------------------
#> ncat4 #levels=:3
#> [1] "III-II" "I" "IV"
#> -----------------------------------------
#> nca4..2 #levels=:2
#> [1] "I-IV" "II-III"
#> -----------------------------------------
drelevel(mena,newlevels=list("I-III"=c("I","II","III"),"IV"="IV")) <- nca4..3 ~ cat4
dlevels(mena)
#> cohort #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> twinnum.f #levels=:2
#> [1] "1" "2"
#> -----------------------------------------
#> cohort.(1975,1977] #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cohort.(1980,1982] #levels=:4
#> [1] "(1980,1982]" "[1973,1975]" "(1975,1977]" "(1977,1980]"
#> -----------------------------------------
#> zyg.1 #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> zyg.DZ #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.[1973,1975] #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zygdz #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.early #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg.2 #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.2 #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cat4 #levels=:4
#> [1] "I" "II" "III" "IV"
#> -----------------------------------------
#> ncat4 #levels=:3
#> [1] "III-II" "I" "IV"
#> -----------------------------------------
#> nca4..2 #levels=:2
#> [1] "I-IV" "II-III"
#> -----------------------------------------
#> nca4..3 #levels=:2
#> [1] "I-III" "IV"
#> -----------------------------------------
drelevel(mena,newlevels=list("I-III"=c("I","II","III"))) <- nca4..4 ~ cat4
dlevels(mena)
#> cohort #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> twinnum.f #levels=:2
#> [1] "1" "2"
#> -----------------------------------------
#> cohort.(1975,1977] #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cohort.(1980,1982] #levels=:4
#> [1] "(1980,1982]" "[1973,1975]" "(1975,1977]" "(1977,1980]"
#> -----------------------------------------
#> zyg.1 #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> zyg.DZ #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.[1973,1975] #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zygdz #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.early #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg.2 #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.2 #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cat4 #levels=:4
#> [1] "I" "II" "III" "IV"
#> -----------------------------------------
#> ncat4 #levels=:3
#> [1] "III-II" "I" "IV"
#> -----------------------------------------
#> nca4..2 #levels=:2
#> [1] "I-IV" "II-III"
#> -----------------------------------------
#> nca4..3 #levels=:2
#> [1] "I-III" "IV"
#> -----------------------------------------
#> nca4..4 #levels=:2
#> [1] "I-III" "IV"
#> -----------------------------------------
drelevel(mena,newlevels=list(group1=c("I","II","III"))) <- nca4..5 ~ cat4
dlevels(mena)
#> cohort #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> twinnum.f #levels=:2
#> [1] "1" "2"
#> -----------------------------------------
#> cohort.(1975,1977] #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cohort.(1980,1982] #levels=:4
#> [1] "(1980,1982]" "[1973,1975]" "(1975,1977]" "(1977,1980]"
#> -----------------------------------------
#> zyg.1 #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> zyg.DZ #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.[1973,1975] #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zygdz #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.early #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg.2 #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.2 #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cat4 #levels=:4
#> [1] "I" "II" "III" "IV"
#> -----------------------------------------
#> ncat4 #levels=:3
#> [1] "III-II" "I" "IV"
#> -----------------------------------------
#> nca4..2 #levels=:2
#> [1] "I-IV" "II-III"
#> -----------------------------------------
#> nca4..3 #levels=:2
#> [1] "I-III" "IV"
#> -----------------------------------------
#> nca4..4 #levels=:2
#> [1] "I-III" "IV"
#> -----------------------------------------
#> nca4..5 #levels=:2
#> [1] "group1" "IV"
#> -----------------------------------------
drelevel(mena,newlevels=list(g1=c("I","II","III"),g2="IV")) <- nca4..6 ~ cat4
dlevels(mena)
#> cohort #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> twinnum.f #levels=:2
#> [1] "1" "2"
#> -----------------------------------------
#> cohort.(1975,1977] #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cohort.(1980,1982] #levels=:4
#> [1] "(1980,1982]" "[1973,1975]" "(1975,1977]" "(1977,1980]"
#> -----------------------------------------
#> zyg.1 #levels=:2
#> [1] "MZ" "DZ"
#> -----------------------------------------
#> zyg.DZ #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.[1973,1975] #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zygdz #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.early #levels=:4
#> [1] "[1973,1975]" "(1975,1977]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> zyg.2 #levels=:2
#> [1] "DZ" "MZ"
#> -----------------------------------------
#> cohort.2 #levels=:4
#> [1] "(1975,1977]" "[1973,1975]" "(1977,1980]" "(1980,1982]"
#> -----------------------------------------
#> cat4 #levels=:4
#> [1] "I" "II" "III" "IV"
#> -----------------------------------------
#> ncat4 #levels=:3
#> [1] "III-II" "I" "IV"
#> -----------------------------------------
#> nca4..2 #levels=:2
#> [1] "I-IV" "II-III"
#> -----------------------------------------
#> nca4..3 #levels=:2
#> [1] "I-III" "IV"
#> -----------------------------------------
#> nca4..4 #levels=:2
#> [1] "I-III" "IV"
#> -----------------------------------------
#> nca4..5 #levels=:2
#> [1] "group1" "IV"
#> -----------------------------------------
#> nca4..6 #levels=:2
#> [1] "g1" "g2"
#> -----------------------------------------