tk_select.list(choices, preselect = NULL, multiple = FALSE, title = NULL)NULL. If non-null and
if the string(s) appear in the list, the item(s) are selected
initially.NULL for no title.multiple is false and
no item was selected (or Cancel was used), "" is
returned. If multiple is true and no item was selected (or
Cancel was used) then a character vector of length 0 is returned.
select.list implemented as a Tk
list box plus OK and Cancel buttons. There will be a
scrollbar if the list is too long to fit comfortably on the screen. The dialog box is modal, so a selection must be made or
cancelled before the R session can proceed. Double-clicking on an
item is equivalent to selecting it and then clicking OK.
If Tk is version 8.5 or later, themed widgets will be used.
select.list (a text version except on Windows and the OS X GUI),
menu (whose graphics = TRUE mode uses this
on most Unix-alikes).