Change the bins of a data frame object from a dat_list,
filling in the columns with ones.
change_dat_bin(object, bins)A data frame from a list object read in by r4ss::SS_readdat().
The leading columns, typically Yr, Seas, ... can be anything,
but there must be columns with names that start with a lower-case letter,
followed by integers.
A vector of characters or whatever you want the names of the
new bins to be. Typically, this will be output from setup_bins().
A modified data frame where columns holding old composition data are
removed in their entirety and new columns of ones are filled for each value in
bins.