Map character response values like "PR" or "SD" to numeric values.
aval_resp(arg)1 if arg equals "CR",
2 if arg equals "PR",
3 if arg equals "SD",
4 if arg equals "NON-CR/NON-PD",
5 if arg equals "PD",
6 if arg equals "NE",
7 if arg equals "MISSING",
NA_real_ otherwise
aval_resp(c("CR", "PR", "SD", "NON-CR/NON-PD", "PD", "NE", "MISSING", "ND", NA_character_))
#> [1] 1 2 3 4 5 6 7 NA NA