relsize.sty

% relsize.sty       4.1       Mar 29, 2013
% 
% Setting the font size relative to the current size
% 
% Authored by Donald Arseneau <asnd@triumf.ca> and Matt Swift <swift@bu.edu>.
% (Inspired by smaller.sty author Bernie Cosell)
% 
% This software is contributed to the public domain by its authors, who disclaim
% all copyrights. For people and jurisdictions that do not recognize contribution
% to the public domain, this software is licensed by the terms of the unlicense, 
% <http://unlicense.org/>
%
% commands are:
% \relsize{n}  where n gives the number of steps ("mag-step" = factor of 1.2)
%              to change the size by;  n = 3 changes from \normalsize to 
%              \LARGE size.  Negative n selects smaller fonts. n is an
%              integer (or half-integer).
%
% \smaller = \relsize{-1},  \smaller[n] = \relsize{-n}
% \larger  = \relsize{1},   \larger[n]  = \relsize{n}
%
% \textsmaller{text}, \textlarger{text} - versions that take an argument
%
% \relscale{f}   like \relsize, but instead of scale-steps,
%                the parameter is a scale factor, such as .75
% \textscale{f}{text}
%
% The font-size command nearest the requested size will be used, and if
% the size error is more than \RSpercentTolerance, then the size will
% be adjusted more precisely using \fontsize.  (The default empty 
% \RSpercentTolerance signals automatic handling, choosing the tolerance 
% based on the font declarations.)
%
% \mathsmaller{A}, \mathlarger{B}       - math versions 
%   (The math versions are entirely different from the text versions.)
%
% More comments at the end of this file, and full documentation in
% relsize-doc.pdf

\ProvidesPackage{relsize}[2013/03/29 ver 4.1]

\DeclareRobustCommand\relsize[1]{%
\ifmmode \@nomath\relsize\else
  \begingroup
  % number of demi-magsteps -> \@tempcnta
  \@tempdima#1\p@ \@tempdima2.0002\@tempdima \divide\@tempdima\p@
  \@tempcnta\@tempdima
  % \message{^^JChange \the\@tempcnta\space half-magsteps from \f@size. }%
  % calculate desired target size -> \@tempdimb
  \@tempdimb\f@size\p@
  \ifnum\@tempcnta<\z@ 
    \def\@tempa{.912871}\@tempcnta=-\@tempcnta
  \else
    \def\@tempa{1.09545}%
  \fi
  \@whilenum {\@tempcnta>\z@}\do {%
    \advance\@tempcnta\m@ne
    \@tempdimb\@tempa\@tempdimb}%
    % \message{ target size \the\@tempdimb. }%
  \rs@scaleToB
\fi}

\DeclareRobustCommand\relscale[1]{%
\ifmmode \@nomath\relscale\else
  \begingroup
  \@tempdimb\f@size\p@ \@tempdimb#1\@tempdimb
  \rs@scaleToB
\fi}

\DeclareRobustCommand\textscale[2]{\leavevmode
  \begingroup\relscale{#1}#2\endgroup}

%  Change font size to \@tempdimb.  Follows from \relsize or \relscale
\def\rs@scaleToB{%
  %\message{Change font size from \f@size\space to \the\@tempdimb. }%
  % perform automatic tolerance adjustment, if requested
  \ifx\RSpercentTolerance\@empty \rs@autoTol \fi
  % apply limits
  \ifdim\@tempdimb<\RSsmallest 
      \rs@size@warning{\the\@tempdimb}{small}{\RSsmallest}%
      \@tempdimb=\RSsmallest
  \fi
  \ifdim\@tempdimb>\RSlargest 
      \rs@size@warning{\the\@tempdimb}{large}{\RSlargest}%
      \@tempdimb=\RSlargest 
  \fi
  % Look up that size in list of pre-defined sizes.  Put error of
  % closest match in \@tempdima
  \def\@tempa{\relax}\@tempdima-\@m\p@
  \let\rs@size\rs@lookup  \rs@fontsizes
  %\message{Look up best as \expandafter\string\@tempa, off by \the\@tempdima}%
  % See how close match was (abs difference -> \@tempdima)
  \ifdim\@tempdima<\z@ \@tempdima-\@tempdima\fi
  %  ... percentage error in \@tempdima (as a count)
  %  (messiness to prevent numeric overflows)
  \ifdim\@tempdima<160\p@ \@tempdima 100\@tempdima 
    \ifdim\@tempdimb>\p@ \divide\@tempdima\@tempdimb \fi
    %\message{or \number\@tempdima \@percentchar. }%
  \fi
  % if error is beyond tolerance, append \fontsize adjustment.  
  \ifnum\@tempdima>\RSpercentTolerance
    %\message{Adjust size to \strip@pt\@tempdimb. }%
    \@tempdima1.2\@tempdimb % baselineskip (could be improved)
    \edef\@tempa{\expandafter\noexpand\@tempa \noexpand\fontsize
      {\strip@pt\@tempdimb}{\strip@pt\@tempdima}\noexpand\selectfont}\fi
  % Now execute size-change command \@tempa
  \expandafter\endgroup\@tempa
  %\message{Font size is now \f@size. }%
}

% For each defined font size, compare its actual size to the desired
% size (\@tempdimb) and the error of the best previous match (\@tempdima).
% Record this command (\@tempa) if it is closer.
\def\rs@lookup#1#2{% #1=command #2=size
  \begingroup
  \advance\@tempdimb-#2\relax
  \ifdim\@absVal\@tempdimb<\@absVal\@tempdima % improvement
    \endgroup
    \def\@tempa{#1}%
    \@tempdima#2\relax \advance\@tempdima-\@tempdimb
  \else
    \endgroup
  \fi}
\def\@absVal#1{\ifnum#1<\z@-\fi#1}

% Tolerance for size mis-match (%).  The empty definition triggers
% automatic selection: 5 for scalable fonts, 30 otherwise.

\def\rs@autoTol{%
  \expandafter\expandafter\expandafter\rs@autoTOL
  \expandafter\meaning
  \csname\f@encoding/\f@family/\f@series/\f@shape\endcsname-\delimiter
}
\def\rs@autoTOL#1>#2-#3\delimiter{%
   \ifx\delimiter#3\delimiter % no -
     \def\RSpercentTolerance{30}%
   \else % font size def has -, assume it covers continuum 
     \def\RSpercentTolerance{5}%
   \fi
   % \message{ Automatic tolerance is \RSpercentTolerance. }%
}

%  Warning messages

\newcommand\rs@size@warning[3]{\PackageWarning{relsize}{%
 Font size #1 is too #2.\MessageBreak Using #3 instead}}

% derived commands

\DeclareRobustCommand\larger[1][\@ne]{\relsize{+#1}}
\DeclareRobustCommand\smaller[1][\@ne]{\relsize{-#1}}
\DeclareRobustCommand\textlarger[2][\@ne]{\leavevmode{\relsize{+#1}#2}}
\DeclareRobustCommand\textsmaller[2][\@ne]{\leavevmode{\relsize{-#1}#2}}


% Some initializations.

% Default empty definition triggers auto-tolerance.
% Beware that \providecommand makes \long macro that fails to trigger.

\def\RSpercentTolerance{} 

% The next two aren't the real initializations!  The real ones are done
% in \@tempb below.  The user can change them afterwards.

\def\RSsmallest{999pt}
\def\RSlargest{1pt}

% Right now we assemble a list of the font sizes

\def\rs@size{\noexpand\rs@size\noexpand}
\def\rs@fontsizes{}
\def\@tempa#1{\ifx\@undefined#1\else
  \expandafter\@tempb#1\@empty\relax\relax\delimiter{#1}\fi}
% parse definition of font-size command (like \large)
% #1 = \@setfontsize  #2 = the command (\large) #3 = size #4 = rest
\def\@tempb#1#2#3#4\delimiter#5{%
  \def\@tempc{\protect !\@empty}\def\@tempd{#1!#3}%
  \ifx\@tempc\@tempd   % self-protected: recurse.
    \expandafter\@tempb#2\@empty\relax\relax\delimiter{#5}%
  \else
    \@tempdimb\z@
    \def\@tempc{\@setfontsize !#5}\def\@tempd{#1!#2}%
    \ifx\@tempc\@tempd   % Normal LaTeX2e
      \afterassignment\strip@prefix \@tempdimb #3pt>%
    \else
    \def\@tempc{\@xsetfontsize !#5}\def\@tempd{#1!#2}%
    \ifx\@tempc\@tempd   % AMS  (defines \@xp=\expandafter.  Note: they have their own \larger/\smaller)
      \chardef\@currsizeindex#3\relax
      \edef\@tempc{\@xp\ifcase\@xp\@currsizeindex\@typesizes\fi}%
      \afterassignment\strip@prefix \@tempdimb \@xp\@firstoftwo\@tempc pt>%
    \else
    \def\@tempc{\@setsize !#5}\def\@tempd{#1!#2}%
    \ifx\@tempc\@tempd   % 2.09 style
      \afterassignment\strip@prefix \@tempdimb #3pt>%
    \else
    \def\@tempc{\slide@setsize !#5}\def\@tempd{#1!#2}%
    \ifx\@tempc\@tempd   % seminar
      \afterassignment\strip@prefix \@tempdimb #3pt>%
    \else
    \def\@tempc{\fontsize}\def\@tempd{#1}%
    \ifx\@tempc\@tempd   % simple
      \afterassignment\strip@prefix \@tempdimb #2pt>%
    \else
      %\message{Could not parse meaning of \string#5. }%
    \fi\fi\fi\fi\fi
    % Checked 5 possible definitions
    \ifdim\@tempdimb=\z@ % Failed to parse size from definition
    \else % Take note of this size.
      \edef\rs@fontsizes{\rs@fontsizes\rs@size#5{\the\@tempdimb}}%
      \ifdim\@tempdimb<\RSsmallest \edef\RSsmallest{\the\@tempdimb}\fi
      \ifdim\@tempdimb>\RSlargest \edef\RSlargest{\the\@tempdimb}\fi
      %\message{\string#5 has size \the\@tempdimb. ^^J}%
    \fi
  \fi
}

% examine each (expected) pre-defined font size 
\@tempa\normalsize
\@tempa\small
\@tempa\footnotesize
\@tempa\large
\@tempa\Large
\@tempa\LARGE
\@tempa\scriptsize
\@tempa\tiny
\@tempa\huge
\@tempa\Huge
% moresize.sty
\@tempa\HUGE  
\@tempa\ssmall
% beamer
\@tempa\Tiny 
\@tempa\TINY
% AMS classes
\@tempa\SMALL
\@tempa\Small

%\show\rs@fontsizes

% Check that we recorded sizes for at least two font-size commands.
% Value of \RSpercentTolerance is both a setting and a flag
\ifx\rs@fontsizes\@empty 
   \def\RSpercentTolerance{0}%
\else\ifdim\RSsmallest<\RSlargest\else
   \def\RSpercentTolerance{3}% 
\fi\fi

\ifx\RSpercentTolerance\@empty \else 

  \PackageWarningNoLine{relsize}
     {Failed to get list of defined font sizes.\MessageBreak
      Size scaling will attempt arbitrary sizes.}

  \def\RSsmallest{\p@}%
  \def\RSlargest{100pt}%

\fi

%
% Math commands (completely different)

\DeclareRobustCommand\mathsmaller[1]{\bgroup
  \let\rs@makechoice\rs@makesmallerchoice
  \def\rs@mathatom{#1}%
  \futurelet\@tempa\rs@collect@decor
}
\DeclareRobustCommand\mathlarger[1]{\bgroup
  \let\rs@makechoice\rs@makelargerchoice
  \def\rs@mathatom{#1}%
  \futurelet\@tempa\rs@collect@decor
}

% Collect the tokens that 'decorate' the atom, to apply them directly on the
% symbol, not after the closing brace.
% Math so far is in \rs@mathatom; next tok is \@tempa; continuation is \@tempb
% Don't nest \ifs because token may be \if or \fi or \or...
\def\rs@collect@decor{%
  \let\@tempb\rs@makechoice
  \ifx\@tempa\limits \let\@tempb\rs@collect@one@decor \fi
  \ifx\@tempa\displaylimits \let\@tempb\rs@collect@one@decor \fi
  \ifx\@tempa\nolimits \let\@tempb\rs@collect@one@decor \fi
  \if\noexpand\@tempa^\let\@tempb\rs@collect@two@decor \fi 
  \if\noexpand\@tempa_\let\@tempb\rs@collect@two@decor \fi 
  \ifx\@tempa\sp \let\@tempb\rs@collect@two@decor \fi
  \ifx\@tempa\sb \let\@tempb\rs@collect@two@decor \fi
  \@tempb}
\def\rs@collect@one@decor#1{%
  \expandafter\def\expandafter\rs@mathatom\expandafter{\rs@mathatom#1}%
  \futurelet\@tempa\rs@collect@decor}
\def\rs@collect@two@decor#1#2{\expandafter
  \def\expandafter\rs@mathatom\expandafter{\rs@mathatom#1{\rs@sstyle{#2}}}%
  \futurelet\@tempa\rs@collect@decor}
\let\rs@sstyle\@firstofone

\def\rs@makesmallerchoice{\mathchoice
  {\textstyle \let\rs@sstyle\scriptstyle \rs@mathatom}%
  {\scriptstyle \let\rs@sstyle\scriptstyle \rs@mathatom}%
  {\scriptscriptstyle \let\rs@sstyle\scriptscriptstyle \rs@mathatom}%
  {\scriptscriptstyle \let\rs@sstyle\scriptscriptstyle \rs@mathatom}%
 \egroup}
\def\rs@makelargerchoice{\mathchoice
  {\protected@edef\rs@sstyle##1{%
      \protect\set@fontsize {1}{\f@size}{\f@baselineskip}\protect\selectfont
      \hbox{$\scriptstyle ##1\m@th$}}%
   \mbox{\larger$\displaystyle\rs@mathatom\m@th$}}%
  {\displaystyle \let\rs@sstyle\scriptstyle \rs@mathatom}%
  {\textstyle \let\rs@sstyle\scriptscriptstyle \rs@mathatom}%
  {\scriptstyle \let\rs@sstyle\scriptscriptstyle \rs@mathatom}%
 \egroup}

\endinput
==========================================================

R E L S I Z E . S T Y           ver 4.1       Mar 29, 2013

by Donald Arseneau,  asnd@triumf.ca,  Vancouver, Canada
originally based on smaller.sty by Bernie Cosell,
and combined with the version by Matt Swift, swift@bu.edu.


It is frequently the case that something should be typeset somewhat larger
or smaller than the surrounding text, whatever that size happens to be.
Specifying such sizing commands explicitly makes it difficult to modify the
font sizes of a document at a later time, and makes it hard to write macros
that work at arbitrary sizes.  Relsize.sty defines several commands for LaTeX
to set font sizes relative to the current size.

For i being an integer (or half-integer) magstep increment (like 2),
and optional arg [i] defaulting to i=1,
And f being a scale factor (like 0.75)
And text being the text argument

\relsize{i}     ungrouped size change by i steps
\larger[i]      ungrouped size change by (optional) i steps
\smaller[i]     ungrouped size change by (optional) -i steps
\relscale{f}    ungrouped size change by scale factor f
\textlarger[i]{text}   "text" size enlarged by i steps
\textsmaller[i]{text}  "text" size reduced by i steps
\textscale{f}{text}    "text" sized scaled by factor f


If the size requested is too small or too large, a warning is given, and
the size will only change as far as appropriate, typically \tiny or \Huge.
These limits are controlled by the commands \RSsmallest and \RSlargest, which
get set automatically when relsize.sty is loaded, but you can redefine them
to other length values: \renewcommand\RSlargest{50pt}.

Fine point:  The combination \relsize{n}\relsize{-n} is not guaranteed to 
restore the current font size! 

Typically, the font-size commands do not select fonts at regular size
intervals.  \relsize (and the others) will select, and execute, the command
for the size closest to the desired size.  Then, if the relative difference 
from the target size is more than \RSpercentTolerance a further font-size
selection is made.  By default, \RSpercentTolerance is an empty macro, which
causes automatic selection: "30" (30%) when the current "fontshape" definition
is composed of only discrete sizes, and "5" when the fontshape definition
covers ranges of sizes.  The higher setting for discrete fonts ensures
only the pre-defined sizes get used.  (By default LaTeX uses Computer
Modern fonts at discrete sizes; you get full coverage of sizes by using
\usepackage{type1cm} or various other font packages.)  For special uses, 
or when the font shape definitions are not parsed properly, you can redefine 
the percent tolerance: 
\renewcommand\RSpercentTolerance{10}.

All of the commands described above are text commands; they cannot be used
in math mode.  There are special \mathsmaller and \mathlarger commands
provided, but these do not use the same sizes that the text versions use.
Instead, they step between the usual math "styles" which you can explicitly
set using the commands \displaystyle, \textstyle, \scriptstyle, and
\scriptscriptstyle [see Lamport, LaTeX/Manual (1st ed, p.54); GMS The LaTeX
Companion, p.255].  However, the \mathlarger command will also increase the
size beyond regular \displaystyle by selecting a larger regular font size
(using \larger).  (Yes, this is a kludge, and doesn't work very well, but 
it can still be useful.)  If you want to use this to create big integral 
signs, then you must also load the package "exscale" so that math symbols
can change size.  The sizes selected are: 

Current style       \mathsmaller gives         \mathlarger gives
---------------     ----------------------     ------------------------
\displaystyle       \textstyle (almost same)   \displaystyle in a \larger font
\textstyle          \scriptstyle               \displaystyle (almost same)
\scriptstyle        \scriptscriptstyle         \textstyle
\scriptscriptstyle  \scriptscriptstyle (same)  \scriptstyle

These commands will attempt to attach superscripts and subscripts to the 
symbol as if the symbol were used alone, but math accents and the math 
spacing behave as if the symbol is enclosed in braces (which it is).
Operators should be explicitly declared to use the right operator
type (\mathrel, \mathbin, \mathop) to get the correct spacing.

Due to their oddities, the math larger/smaller commands should not be 
trusted blindly, and they will not be useful in every instance.


Donald Arseneau                         asnd@triumf.ca