How can you make a macron less wide?

Question

Macrons appear really wide on all characters, but especially so on the i. Is it possible to make them less wide?

\documentclass{article}
\begin{document}
Tac\=e, M\=arc\=o, \=unus, f\=\i li\=\i?
\end{document}

Answer 1

You can define a short one that matches the longer ones and fits quite well on the i like this:

\newcommand{\shortmacron}{%
   \makebox[0pt][l]{%
      \rule[1.3ex]{0.2em}{0.035em}%
   }%
}

Another way is to define a smart version that automatically adapts it’s length. I also set this one a little lower to minimize the conflict with the drop serif of the f

\newlength\tmp
\newcommand{\smartmacron}[1]{%
   \settowidth{\tmp}{#1}%
   \makebox[\tmp][c]{%
      \rule[1.2ex]{0.6\tmp}{0.035em}%
   }\kern-\tmp#1%
}

Using the xstring package to check which letter follows, we can define the macro even more smart and align the macron better on top of the letter:

\usepackage{xstring}
\newlength\tmpa
\newlength\tmpb
\newlength\tmpc
\newcommand{\supersmartmacron}[1]{%
   \settowidth{\tmpa}{#1}% width of letter
   \setlength{\tmpb}{0em}% x-shift
   \setlength{\tmpc}{1.23ex}% raise
   \IfStrEqCase{#1}{%
      {a} {\setlength{\tmpb}{-0.04em}}%
      {e} {\setlength{\tmpb}{-0.01em}}%
      {i} {\setlength{\tmpb}{-0.045em}\setlength{\tmpc}{1.8ex}}%
      {\i}{\setlength{\tmpb}{-0.045em}}%
      {o} {\setlength{\tmpb}{-0.01em}}%
      {u} {\setlength{\tmpb}{-0.04em}}%
   }
   \makebox[\tmpa][c]{%
      \kern\tmpb\rule[\tmpc]{0.6\tmpa}{0.035em}%
   }\kern-\tmpa#1%
}

Of curse the right values for the lengthen \tmpa, \tmpb and \tmpc depend on the selected typeface.

Result and demo code
(original macron, short macron, smart macron, super smart macron)

\documentclass{article}

\newcommand{\shortmacron}{%
   \makebox[0pt][l]{%
      \rule[1.3ex]{0.2em}{0.035em}%
   }%
}

\newlength\tmp
\newcommand{\smartmacron}[1]{%
   \settowidth{\tmp}{#1}%
   \makebox[\tmp][c]{%
      \rule[1.2ex]{0.6\tmp}{0.035em}%
   }\kern-\tmp#1%
}

\usepackage{xstring}
\newlength\tmpa
\newlength\tmpb
\newlength\tmpc
\newcommand{\supersmartmacron}[1]{%
   \settowidth{\tmpa}{#1}% width of letter
   \setlength{\tmpb}{0em}% x-shift
   \setlength{\tmpc}{1.23ex}% raise
   \IfStrEqCase{#1}{%
      {a} {\setlength{\tmpb}{-0.04em}}%
      {e} {\setlength{\tmpb}{-0.01em}}%
      {i} {\setlength{\tmpb}{-0.045em}\setlength{\tmpc}{1.8ex}}%
      {\i}{\setlength{\tmpb}{-0.045em}}%
      {o} {\setlength{\tmpb}{-0.01em}}%
      {u} {\setlength{\tmpb}{-0.04em}}%
   }
   \makebox[\tmpa][c]{%
      \kern\tmpb\rule[\tmpc]{0.6\tmpa}{0.035em}%
   }\kern-\tmpa#1%
}

\begin{document}
%\huge
%\tiny
Tac\=e, M\=arc\=o, \=unus, f\=\i li\=\i?

Tac\shortmacron e, M\shortmacron arc\shortmacron o, \shortmacron unus, f\shortmacron\i li\shortmacron\i?

Tac\smartmacron e, M\smartmacron arc\smartmacron o, \smartmacron unus, f\smartmacron\i li\smartmacron\i?

Tac\supersmartmacron e, M\supersmartmacron arc\supersmartmacron o, \supersmartmacron unus, f\supersmartmacron\i li\supersmartmacron\i?

\=a \shortmacron a

\=a \smartmacron a

\=a \supersmartmacron a\quad
\=e \supersmartmacron e\quad
\=i \supersmartmacron i\quad
\=\i \supersmartmacron \i\quad
\=o \supersmartmacron o\quad
\=u \supersmartmacron u\quad

\supersmartmacron a\quad
\supersmartmacron e\quad
\supersmartmacron i\quad
\supersmartmacron \i\quad
\supersmartmacron o\quad
\supersmartmacron u\quad
\end{document}

---

To use the shortcut with on of the smart versions call

\let\=\supersmartmacron

in your preamble.

Answer 2

Tobi's answer works wonderfully for lowercase letters in an upright font. I found myself putting macrons on uppercase letters in an Italic font, so I tweaked it to default to the letter's height and to apply a slant correction:

% \withoutpt as in the public domain file `samplepdf.tex'
{\catcode`\p=12 \catcode`\t=12 \gdef\WITHOUTPT#1pt{#1}}
 \def\withoutpt#1{\expandafter\WITHOUTPT#1} % returns float-like string
% New dimension to deal with slanted fonts
\newlength\macronitalcorr
% Let's name some of Tobi's parameters
\newlength\macrongap
\newlength\macronthickness
\setlength{\macrongap}{0.23ex}% 
\setlength{\macronthickness}{0.035em}% thickness
\newcommand{\macronscale}{0.6} % Fraction of letter covered
% I have too many parameters--I can't remember what \tmpa means!
\newlength\macronletterwidth % \tmpa
\newlength\macronadjustment % \tmpb
\newlength\macronheight % \tmpc
\newcommand{\superdupersmartmacron}[1]{{% 
   % Extra brackets so commands will automatically reset
   \setlength{\macronadjustment}{0em}% x-shift
   \def\macroninputletter{#1}%
   \IfStrEqCase{#1}{%
      {a} {\setlength{\macronadjustment}{-0.04em}}%
      {e} {\setlength{\macronadjustment}{-0.01em}}%
      {i} {\setlength{\macronadjustment}{-0.045em}%
            \def\macronscale{0.95}% Wider macron over i
            \def\macroninputletter{\i}}% % Automatically use \i for i
      {I} {\def\macronscale{0.95}}% Wider macron over I
      {\i}{\setlength{\macronadjustment}{-0.045em}%
            \def\macronscale{0.95}}% Wider macron over i
      {o} {\setlength{\macronadjustment}{-0.01em}}%
      {u} {\setlength{\macronadjustment}{-0.04em}}%
   }
   \settoheight{\macronheight}{\macroninputletter}%
   \addtolength{\macronheight}{\macrongap}%
   %
   % If the font slants, how much do we move the macron?
   \macronitalcorr = \withoutpt\the\fontdimen 1 \the\font \macronheight 
   %
   \settowidth{\macronletterwidth}{\macroninputletter}% width of letter
   \makebox[\macronletterwidth][c]{%
      \kern\macronadjustment%
      \kern \macronitalcorr
      \rule[\macronheight]{\macronscale\macronletterwidth} 
                          {\macronthickness}%
     \kern -\macronitalcorr%
   }\kern-\macronletterwidth\macroninputletter%
}}

(A few other bells and whistles--I wanted macrons over is to be wider and to automatically replace i with \i.)