change borders of selected rows and columns of a flextable.
This function is not to be used by end user (it requires careful
settings to avoid overlapping borders) but only for programming purposes.
If you need to add borders, use instead other functions:
These set borders for the whole table : border_outer()
,
border_inner_h()
and border_inner_v()
.
All the following functions also support the
row and column selector i
and j
:
If you want to highlight specific cells with some borders, use
surround()
.