umx (version 4.20.0)

umx_paste_names: Concatenate base variable names with suffixes to create wide-format variable names (i.e twin-format)

Description

It's easier to work with base names, rather than the twice-as-long hard-to-typo list of column names. umx_paste_names adds suffixes to names so you can work with that nice short list. So, you provide bmi, and you get back fully specified family-wise names: c("bmi_T1", "bmi_T2")

note: tvars is a shortcut for umx_paste_names

Usage

umx_paste_names(
  varNames,
  sep = "",
  suffixes = 1:2,
  covNames = NULL,
  prefix = NULL
)

Value

• vector of suffixed var names, i.e., c("v1_T1", "v2_T1", "v1_T2", "v2_T2", "cov_T1", "cov_T2")

Arguments

varNames

a list of base names, e.g c("bmi", "IQ")

sep

A string separating the name and the twin suffix, e.g. "_T" (default is "")

suffixes

a list of terminal suffixes differentiating the twins default = 1:2)

covNames

a list of base names for covariates (to be sorted last in list), e.g c("age", "sex")

prefix

a string to prepend to each label, e.g "mean" -> "mean_age" "mean_sex"

Details

Method 1: Use complete suffixes

You can provide complete suffixes like "_T1" and "_T2". This has the benefit of being explicit and very general:

umx_paste_names(c("var1", "var2"), suffixes = c("_T1", "_T2"))

Note: for quick typing, tvars is an alias for umx_paste_names

Method 2: Use sep and a suffix vector.

Alternatively, you can use sep to add a constant like "_T" after each basename, along with a vector of suffixes. This has the benefit of showing what is varying: This is then suffixed with e.g. "1", "2".

umx_paste_names(c("var1", "var2"), sep = "_T", suffixes = 1:2)

Working with covariates

If you are using umxACEcov(), you need to keep all the covariates at the end of the list. Here's how:

umx_paste_names(c("var1", "var2"), cov = c("cov1"), sep = "_T", suffixes = 1:2)

note: in conventional twin models, the expCov matrix is T1 vars, followed by T2 vars. For covariates, you want T1vars, T2 vars, T1 covs, T2 covs. This is what covNames accomplishes.

References

• https://tbates.github.io, https://github.com/tbates/umx

See Also

namez() umx_explode_twin_names()

Other String Functions: umx_explode_twin_names(), umx_explode(), umx_grep(), umx_names(), umx_rot(), umx_str_chars(), umx_str_from_object(), umx_trim(), umx

Examples

# two styles doing the same thing: first is more general
umx_paste_names("bmi", suffixes = c("_T1", "_T2"))
umx_paste_names("bmi", sep = "_T", suffixes = 1:2)
varNames = umx_paste_names(c("N", "E", "O", "A", "C"), "_T", 1:2)
umx_paste_names(c("IQ", "C"), cov = c("age"), sep = "_T", suffixes = 1:2)
umx_paste_names(c("IQ", "C"), cov = c("age"), sep = "_T", prefix= "mean_")
# For quick-typing, tvars is an alias for umx_paste_names
tvars(c("IQ", "C"), cov = "age", sep = "_T", prefix= "mean_")
tvars("IQ")