Question

in multifaceted plot how many rows will be formed when facets is mentioned as facets=.~drv

Answer 1

"facets = .~drv means there is only one row and more than one column will be there in your graphs and columns depends on the number of factors, what you are giving to the function.

And

facets = drv~. means there is only one column and more than one row will be there in your graphs and rows depends on the number of factors, what you are giving to the function.

"