The initial grob matrix object with column names edited in the appropriate
areas.
Arguments
mat
The grob matrix object the column names will be edited in.
column_names
The replacement column names,
in a list with each column name a separate element. The list must have
the same amount of elements as the column_name_cols parameter.
column_name_cols
Which column positions of the initial data frame / matrix the column_names
will replace, in a list with each column name's column positions a separate element.
The list must have the same amount of elements as the column_names parameter.
Can either be numeric indices, or column names of the initial data frame / matrix
passed through grob_matrix.
Default is an empty list. If unaltered, the function will assume the user
wants to apply column_names to all columns of the grob_matrix -
in which case only one column_names is allowed.
group_elements
A boolean argument on whether like, adjacent column names
should be grouped together.
Details
The user can only use this function if the initial data frame / matrix
passed through grob_matrix had column names to begin with.
The underlying column names will be unaffected. So, if the user wants to use
alter_at afterwards, he/she should select the original column names
and not the replacements from this function.