Consolidating duplicate rows in a dataframe [duplicate]

Answer 1

The following solution using the ‹dplyr› and ‹tidyr› packages should do what you want:

df %>%
    group_by(Protein2, Protein3, Protein4) %>%
    nest() %>%
    mutate(Biomarker1 = lapply(data, `[[`, 'Biomarker1'),
           Biomarker1 = unlist(lapply(Biomarker1, paste, collapse = ', '))) %>%
    ungroup() %>%
    # Restore the “Beginning1” column is a bit of work, unfortunately.
    mutate(Beginning1 = lapply(data, `[[`, 'Beginning1'),
           Beginning1 = unlist(lapply(Beginning1, `[[`, 1))) %>%
    select(-data)

Answer 2

This is a dplyr solution which should yield the expected result.

library(dplyr)

df <- df %>%
      group_by(Beginning1, Protein2, Protein3, Protein4) %>%
      summarise(Biomarker1 = paste(Biomarker1, collapse = ", "))