当我使用 tkz-fct 简化分数时，我希望格式化以便负数位于分数前面

Question

我找到了一种使用以下代码简化分数的方法。我想修改它，以便如果结果分数为负数，则将负数显示在分数前面。

\documentclass{exam}
   \usepackage{mathtools}%includes amsmath
   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   \usepackage{tkz-fct}%%must be loaded before tkz
   \newcommand*{\fracReducedTkz}[2]{\tkzReducFrac{#1}{#2}\ensuremath{\ifnum\tkzMathSecondResult=1
       \tkzMathFirstResult
       \else\ifnum\tkzMathSecondResult=-1
       \number\numexpr-1*\tkzMathFirstResult
       \else\ifnum\tkzMathSecondResult<0
       \frac{\number\numexpr-1*\tkzMathFirstResult}{\number\numexpr-1*\tkzMathSecondResult}
       \else
       \frac{\tkzMathFirstResult}{\tkzMathSecondResult}\fi\fi\fi}}%
   
   \usepackage{tikz}
   \begin{document}
   \[\fracReducedTkz{-3}{4}\]
   
   \[\fracReducedTkz{3}{-4}\]
   
   %%This is how I would like to see it displayed
   \[-\frac{3}{4}\]
   \end{document}

Answer 1

我不确定我的数学是否完全正确，但我对你的代码做了三处修改：

1. \tkzMathSecondResult<0对于我-在前面放置 a\frac并从第一个参数中删除与 -1 的乘法的情况\frac
2. 我添加了一个，\else用于表示在之前\tkzMathFirstResult<0带有一个的情况，并将第一个参数乘以 -1（第二个参数保持原样）-\frac
3. 我\fi在最后添加了一个额外内容来结束\else引入的额外内容

\documentclass{exam}
   \usepackage{mathtools}%includes amsmath
   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   \usepackage{tkz-fct}%%must be loaded before tkz
   \newcommand*{\fracReducedTkz}[2]{\tkzReducFrac{#1}{#2}\ensuremath{\ifnum\tkzMathSecondResult=1
       \tkzMathFirstResult
       \else\ifnum\tkzMathSecondResult=-1
       \number\numexpr-1*\tkzMathFirstResult
       \else\ifnum\tkzMathSecondResult<0
       -\frac{\tkzMathFirstResult}{\number\numexpr-1*\tkzMathSecondResult}
       \else\ifnum\tkzMathFirstResult<0
       -\frac{\number\numexpr-1*\tkzMathFirstResult}{\tkzMathSecondResult}
       \else
       \frac{\tkzMathFirstResult}{\tkzMathSecondResult}\fi\fi\fi\fi}}%
   
   \usepackage{tikz}
   \begin{document}
   \[\fracReducedTkz{-3}{4}\]
   
   \[\fracReducedTkz{3}{-4}\]
   
   %%This is how I would like to see it displayed
   \[-\frac{3}{4}\]
   \end{document}

结果：