数学字体改变和 siunitx？

Question

好吧，经过大量的\trace思考，我想我已经解决了它：

测试3.png

...但我对这个解决方案感到很困惑，因此如果能给出更博学的答案我将不胜感激。

首先，在跟踪中注意到这一点：

\__siunitx_font_weight: ->\unboldmath \mdseries
\unboldmath ->\@nomath \unboldmath \mathversion {normal}

因此，无论\mathversion您选择哪一个 -siunitx都会切换到normal，显然每次执行\SI命令时都会切换到。

因此，每次更改字体时，我们基本上都需要\SetSymbolFont重新进行数学版本；不幸的是，该命令是- 因此大多数代码实际上是一种可以在任何地方工作的黑客提供的代码。normal\@onlypreamble\ReSetSymbolFont

最令人费解的是，执行\ReSetSymbolFont{upright} {normal}不会产生任何效果 - 而实际上似乎起作用的是\ReSetSymbolFont{operators} {normal}。我真的说不出来 - 为什么operators（显然只有该字体）会对产生影响\SI？

无论如何，这里是代码：

\documentclass{article}

\usepackage[utf8]{inputenc}
\usepackage[T2A, T1]{fontenc}
\usepackage{amsmath}
\usepackage{lmodern}
\usepackage{siunitx}
\usepackage{mathpazo}
\usepackage{etoolbox}% patchcmd
\usepackage{trace}

% http://tex.stackexchange.com/questions/19255/using-declaremathversion
% note: mathpazo.sty, lmodern.sty overrides normal, bold!
%%% New math versions
\DeclareMathVersion{lmnormal}
\DeclareMathVersion{lmbold}
\DeclareMathVersion{mpazonormal}
\DeclareMathVersion{mpazobold}
\newcommand\lmmath{\mathversion{lmnormal}}
\newcommand\lmboldmath{\mathversion{lmbold}}
\newcommand\mpmath{\mathversion{mpazonormal}}
\newcommand\mpboldmath{\mathversion{mpazobold}}

%%% Math symbol fonts
% lmodern.sty
\SetSymbolFont{operators}   {lmnormal}{OT1}{lmr} {m}{n}
\SetSymbolFont{letters}     {lmnormal}{OML}{lmm} {m}{it}
\SetSymbolFont{symbols}     {lmnormal}{OMS}{lmsy}{m}{n}
\SetSymbolFont{largesymbols}{lmnormal}{OMX}{lmex}{m}{n}
\SetSymbolFont{operators}   {lmbold}  {OT1}{lmr} {bx}{n}
\SetSymbolFont{letters}     {lmbold}  {OML}{lmm} {b}{it}
\SetSymbolFont{symbols}     {lmbold}  {OMS}{lmsy}{b}{n}
\SetSymbolFont{largesymbols}{lmbold}  {OMX}{lmex}{m}{n}
% add for \SI?
\SetSymbolFont{upright}   {lmnormal}{OT1}{lmr} {m}{n}
% mathpazo.sty
\SetSymbolFont{operators}   {mpazonormal}  {OT1}{ppl}{m}{n}
\SetSymbolFont{upright}     {mpazonormal}  {OT1}{zplm}{m}{n}
\SetSymbolFont{letters}     {mpazonormal}  {OML}{zplm}{m}{it}
\SetSymbolFont{symbols}     {mpazonormal}  {OMS}{zplm}{m}{n}
\SetSymbolFont{largesymbols}{mpazonormal}  {OMX}{zplm}{m}{n}

\SetSymbolFont{operators}   {mpazobold}   {OT1}{ppl}{b}{n}
\SetSymbolFont{upright}     {mpazobold}     {OT1}{zplm}{b}{n}
\SetSymbolFont{letters}     {mpazobold}     {OML}{zplm}{b}{it}
\SetSymbolFont{symbols}     {mpazobold}     {OMS}{zplm}{b}{n}
\SetSymbolFont{largesymbols}{mpazobold}{OMX}{zplm}{m}{n}

%%% Math alphabets, at most 16 families
% lmodern.sty
\SetMathAlphabet{\mathbf}{lmnormal}{OT1}{lmr}{bx}{n}
\SetMathAlphabet{\mathsf}{lmnormal}{OT1}{lmss}{m}{n}
\SetMathAlphabet{\mathit}{lmnormal}{OT1}{lmr}{m}{it}
\SetMathAlphabet{\mathtt}{lmnormal}{OT1}{lmtt}{m}{n}
\SetMathAlphabet{\mathbf}{lmbold}  {OT1}{lmr}{bx}{n}
\SetMathAlphabet{\mathsf}{lmbold}  {OT1}{lmss}{bx}{n}
\SetMathAlphabet{\mathit}{lmbold}  {OT1}{lmr}{bx}{it}
\SetMathAlphabet{\mathtt}{lmbold}  {OT1}{lmtt}{m}{n}

% mathpazo.sty
\SetMathAlphabet{\mathit}{mpazonormal} {OT1}{ppl}{m}{it}
\SetMathAlphabet{\mathit}{mpazobold}   {OT1}{ppl}{b}{it}
\SetMathAlphabet{\mathbf}{mpazonormal}     {OT1}{zplm}{b}{n}
\SetMathAlphabet{\mathbold}{mpazonormal}   {OML}{zplm}{b}{it}

% http://tex.stackexchange.com/questions/35287/sans-serif-font-with-siunitx
% \SI % "By default, all text is typeset in the current upright, serif math font."
% \sisetup{detect-all} %

% latex.ltx - \SetSymbolFont
\makeatletter
% \cdp@list ->\@latex@error {Can be used only in preamble}\@eha
% \SetSymbolFont@ ->\@latex@error {Can be used only in preamble}\@eha
% \version@list ->\@latex@error {Can be used only in preamble}\@eha
% \group@list ->\@latex@error {Can be used only in preamble}\@eha
% \get@cdp ->\@latex@error {Can be used only in preamble}\@eha
%
% just a \let seems enough for this:
\let\Recdp@list\cdp@list
% no need for this:
% \expandafter\def\expandafter\Recdp@list\expandafter{\cdp@list}%\show\Recdp@list
%
\let\Reversion@list\version@list
\let\Regroup@list\group@list
\let\Reget@cdp\get@cdp
%
% \expandafter\def\expandafter\ReSetSymbolFont@\expandafter{\SetSymbolFont@}\show\ReSetSymbolFont@ % fails w 'Argument of \SetSymbolFont@ has an extra }.'
%
% \tracingpatches
% \let\ReSetSymbolFont@\SetSymbolFont@
% \patchcmd{\ReSetSymbolFont@}{\version@list}{\Reversion@list}{\typeout{success}}{\typeout{failure}} % -- macro cannot be retokenized cleanly; failure
%
\def\ReSetSymbolFont#1#2#3#4#5#6{%
 \@tempswafalse
 \edef\reserved@b{#3}%
 \def\cdp@elt##1##2##3##4{\def\reserved@c{##1}%
      \ifx\reserved@b\reserved@c \@tempswatrue\fi}%
 \Recdp@list%\cdp@list
 \if@tempswa
  \expandafter\ReSetSymbolFont@
    \csname mv@#2\expandafter\endcsname\csname#3/#4/#5/#6\expandafter
    \endcsname \csname sym#1\endcsname
 \else
  \@latex@error{Encoding scheme  `#3' unknown}\@eha
 \fi
}
% \@onlypreamble\SetSymbolFont
% \def\@onlypreamble#1{%
%   \expandafter\gdef\expandafter\@preamblecmds\expandafter{%
%        \@preamblecmds\do#1}}
%
\def\ReSetSymbolFont@#1#2#3{%
  \expandafter\in@\expandafter#1\expandafter{\Reversion@list}%
  \ifin@
    \expandafter\in@\expandafter#3\expandafter{\Regroup@list}%
    \ifin@
      \begingroup
        \expandafter\Reget@cdp\string#2\@nil\reserved@a
        \toks@{}%
        \def\install@mathalphabet##1##2{%
             \addto@hook\toks@{\install@mathalphabet##1{##2}}%
            }%
        \def\getanddefine@fonts##1##2{%
          \ifnum##1=#3%
             \addto@hook\toks@{\getanddefine@fonts#3#2}%
             \expandafter\Reget@cdp\string##2\@nil\reserved@b
             \ifx\reserved@a\reserved@b\else
                \@font@info{Encoding `\reserved@b' has changed
                    to `\reserved@a' for symbol font\MessageBreak
                   `\expandafter\@gobblefour\string#3' in the
                    math version `\expandafter
                    \@gobblefour\string#1'}%
             \fi
             \@font@info{%
                Overwriting symbol font
                `\expandafter\@gobblefour\string#3' in
                 version `\expandafter
                \@gobblefour\string#1'\MessageBreak
                \@spaces \expandafter\@gobble\string##2 -->
                         \expandafter\@gobble\string#2}%
          \else
             \addto@hook\toks@{\getanddefine@fonts##1##2}%
          \fi}%
         #1%
         \xdef#1{\the\toks@}%
      \endgroup
    \else
       \@latex@error{Symbol font `\expandafter\@gobblefour\string#3'
                  not defined}\@eha
    \fi
  \else
    \@latex@error{Math version `\expandafter\@gobblefour\string#1'
       is not
       defined}{You probably misspelled the name of the math
       version.^^JOr you have to specify an additional package.}%
  \fi
}
\makeatother


\begin{document}

\fontfamily{lmr}\selectfont% change text font to lmodern
\renewcommand{\rmdefault}{lmr}%
% \sisetup{detect-all}
% \mathversion{normal}% just testing
% \traceon
% \ReSetSymbolFont{upright}   {normal}{OT1}{lmr} {m}{n} % lmnormal; nope
\ReSetSymbolFont{operators}   {normal}{OT1}{lmr} {m}{n} % lmnormal - this is the one, that seemingly works?

\makeatletter
This is Lmodern font \math@version. $a^2 + b^2 = c^2; \mathrm{ms}$. $20$ ms, \fbox{\SI{20}{\meter\per\second}}

\mpmath
\def\defaultscriptratio{.76}
\def\defaultscriptscriptratio{.6}
% \sisetup{detect-all}
% \ReSetSymbolFont{upright}     {normal}  {OT1}{zplm}{m}{n} % mpazonormal; nope
\ReSetSymbolFont{operators}   {normal}  {OT1}{ppl}{m}{n} % mpazonormal

This is Mathpazo font \math@version. $a^2 + b^2 = c^2; \mathrm{ms}$. $20$ ms, \fbox{\SI{20}{\meter\per\second}}


\lmmath
\def\defaultscriptratio{.7}
\def\defaultscriptscriptratio{.5}
% \sisetup{detect-all}
% \ReSetSymbolFont{upright}   {normal}{OT1}{lmr} {m}{n} % lmnormal; nope
\ReSetSymbolFont{operators}   {normal}{OT1}{lmr} {m}{n} % lmnormal

This is LModern font \math@version. $a^2 + b^2 = c^2; \mathrm{ms}$. $20$ ms, %
% \traceon%
\fbox{\SI{20}{\meter\per\second}}%
% \traceoff

\makeatother
\end{document}

Answer 1