Are there any formal guidelines/suggestions on the use of \midrule
inside a booktabs
table with just rows of identically formatted data? The booktabs manual is very specific about vertical rules, stating that you should
[n]ever, ever use vertical rules.
But what about horizontal rules between data items of the same type?
This question occurred when deciding if a LaTeX table generator should insert \midrule
s between each line. The picture below (shamelessly stolen from there) shows the difference for the same data (but with slightly different formatting of the figures):
Best Answer
The
\midrule
instruction generates a horizontal line that's (i) a bit thinner than either\toprule
or\bottomrule
and (ii) provides some extra vertical spacing both above and below the rule. As such, a\midrule
is best used to separate a table's header row(s) from the body of the table, and a table's body from the footer material (if present, of course).If the table contains rows and rows of identically formatted data but no header or footer components, I would not use a
\midrule
at all. Inserting a\midrule
between each and every row constitutes, to me at least, a violation of the spirit of thebooktabs
package that's nearly as egregious as using vertical rules. :-)If it's absolutely necessary to provide some separation between the rows, I'd either adjust the amount of default vertical space or add a bit of extra vertical space -- via an instruction such as
\\[0.5ex]
-- after every fifth row or so. The amount of extra space will depend on the table's width: the wider the table, the more whitespace should be inserted after a group of rows.Addendum: Here's a comparison of the look of the table you've linked to in your posting, first with all midrules present, and second with a midrule used only to separate the header material from the table's body. (I've also applied a few additional tweaks, such as inserting a touch of extra vertical space after the third row). I believe most readers will find the second table to be more readable -- and certainly much less cluttered -- than is the first.