Adds width space between the columns or height space between
the rows.
gtable_add_col_space(x, width)
gtable_add_row_space(x, height)
Arguments
| x |
a gtable object |
| width |
a vector of units of length 1 or ncol - 1 |
| height |
a vector of units of length 1 or nrow - 1 |