Link the observations and the panel with a line

Usage

mark_line(..., .element = NULL)

...: <dyn-dots> A list of formulas, where each side of the formula should be an integer or character index of the original data, or a range_link() object defining the linked observations. Use NULL to indicate no link on that side. You can also combine these by wrapping them into a single list(). If only the left-hand side of the formula exists, you can input it directly. For integer indices, wrap them with I() to use the ordering from the layout. You can also use waiver() to inherit values from the other group.
.element: A element_line() object. Vectorized fields will be recycled to match the total number of groups, or you can wrap the element with I() to recycle to match the drawing groups. The drawing groups typically correspond to the number of observations, as each observation will be linked with the plot panel.