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Identify surrogate-measurement columns in a data frame

Source: R/utils.R
extract_surrogate_cols.Rd

Returns the names of columns matching a regex pattern. The default "^W[0-9]+$" matches W1, W2, ... and corresponds to the convention used by generate_aft_data() and the manuscript notation.

Usage

extract_surrogate_cols(data, pattern = "^W[0-9]+$")

Arguments

data

A data frame.

pattern

A regular expression. Defaults to "^W[0-9]+$".

Value

A character vector of column names, in the order they appear in data. Throws an error if no columns match.

Examples

sim <- generate_aft_data(n = 50, n_val = 20, seed = 1)
extract_surrogate_cols(sim$survival)
#> [1] "W1" "W2" "W3"