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If you have a function f, it is common to denote its mean value by a line over it, like \bar u. Suppose I have a function like $f_T$, then how should I write the mean value?

Like $\bar f_T$, $\overline{f}_T$ or $\overline{f_T}$? Or something else? Please advise me!!!

AboAmmar
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MathematicianInWaiting
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1 Answers1

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This seems a matter of preference to me. I personally always prefer to use \overline, as I find the \bar line to be very short (particularly if you have something wider than a single letter, like f_T). Apart from that preference, I'd point out two small differences between including the _T under the line, or not.

  • If by the mean of f_T, you mean: the mean of f, and afterwards specifying some T, I would suggest \overline{f}_T
  • If f_T is the actual function you are taking a mean of, I would suggest \overline{f_T}

By your description, I would suggest the second.

In general, if you are unsure, you can always make a command

\newcommand*\mean[1]{\overline{#1}}

and use \mean{f_T}, so you can change to \bar if you'd prefer that at a later point.

Erik Rijcken
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  • Thanks. Do you know a code, like your new command, where it would treat \mean{f} and \mean{f_T} differently? So for functions with a parameter like T I can choose to display it differently, with the same command? – MathematicianInWaiting Aug 14 '15 at 10:51
  • Do you mean (haha!) \mean{f_T} should not be stretch over _{T}? – Bernard Aug 14 '15 at 11:38