计算分数考试类

Question

我想通过将百分比乘以总分数（例如 0.5 * \numpoints{}）来计算考试的评分分数，以制作评分表。问题是，在运行编译之前，我无法将 \numpoints 作为数字访问，并且会出现错误。我一直试图使用某种 if 语句来解决这个问题，但没有任何用处。下面是一个可行的示例，我当前的解决方案是注释这些行，编译文件，然后取消注释并再次编译。有没有一种简单的方法可以使用 if 语句来解决这个问题？

\documentclass[addpoints, 12pt]{exam}
\printanswers
\usepackage[utf8]{inputenc}
\usepackage{fp}

\begin{document}
\Large{Exam}\\

% Marking points COMMENT line 1-3 below to run first time
\FPeval{\gradethree}{clip(\numpoints{} * 0.5)}
\FPeval{\gradefour}{clip(\numpoints{} * 0.67)}
\FPeval{\gradefive}{clip(\numpoints{} * 0.83)}

% Marking table COMMENT lines 2-4 below to run first time
\noindent{}Total points: \numpoints{} \\
Grade 3:  \gradethree \space points \\
Grade 4:  \gradefour  \space points \\
Grade 5:  \gradefive  \space points \\

\begin{questions}

\question[2]
Who is Mark Twain?
\begin{solution}
Not your daddy.
\end{solution}

\question[2]
Who is Mark Twain?
\begin{solution}
Not your daddy.
\end{solution}

\question[2]
Who is Mark Twain?
\begin{solution}
Not your daddy.
\end{solution}

\question[2]
Who is Mark Twain?
\begin{solution}
Not your daddy.
\end{solution}

\end{questions}


\end{document}

我的评论解决方法之后的输出如下所示（这正是我想要实现的）：

Answer 1

ifthenx提供此功能的包\ispositiveinteger可以达到这个目的：

\documentclass[addpoints, 12pt]{exam}
\printanswers
\usepackage[utf8]{inputenc}
\usepackage{fp}
\usepackage{ifthenx}

\begin{document}
\noindent\Large{Exam}\\

% calculates marking points for exam grades
\ifthenelse{\ispositiveinteger{\numpoints}}
    {   \FPeval{\gradethree}{clip(\numpoints{} * 0.5)}
        \FPeval{\gradefour}{clip(\numpoints{} * 0.67)}
        \FPeval{\gradefive}{clip(\numpoints{} * 0.83)}  }

% grading table:
\noindent{}Total points: \numpoints{} \\
\ifthenelse{\ispositiveinteger{\numpoints}}
    {   Grade 3:  \gradethree \space points \\
        Grade 4:  \gradefour  \space points \\
        Grade 5:  \gradefive  \space points \\  }
    % Printed if \numpoints is not available.
    {Sorry no grading table \textbf{yet}.}
    
\normalsize
\begin{questions}

\question[2]
Who is Mark Twain?
\begin{solution}
Not your daddy.
\end{solution}

\question[2]
Who is Mark Twain?
\begin{solution}
Not your daddy.
\end{solution}

\question[2]
Who is Mark Twain?
\begin{solution}
Not your daddy.
\end{solution}

\question[2]
Who is Mark Twain?
\begin{solution}
Not your daddy.
\end{solution}

\end{questions}


\end{document}

当存在时，当然会给出与上面相同的输出numpoints，否则会打印标记表不可用。