我正在尝试插入一个带有“C”的积分符号。具体来说,我需要 Unicode 字符 U+2A10,其形式为:⨐ 。
我不想使用 stix 包或 XeLaTex。
谢谢!
答案1
这是叠加在积分符号上的无衬线字体 c:
\documentclass{article}
\usepackage{amsmath}
\newcommand{\circint}{\mathop{\mathpalette\docircint\relax}\!\int}
\newcommand{\docircint}[2]{%
\ifx#1\displaystyle
\displaycircint
\else
\normalcircint{#1}%
\fi
}
\newcommand{\displaycircint}{\displaystyle\mathsf{c}\mkern-18mu}
\newcommand{\normalcircint}[1]{%
\smallerc{#1}\ifx#1\textstyle\mkern-9mu\else\mkern-8.2mu\fi
}
\newcommand{\smallerc}[1]{%
\vcenter{\hbox{$\ifx#1\textstyle\scriptstyle\else\scriptscriptstyle\fi\mathsf{c}$}}%
}
\begin{document}
$\displaystyle A+\int_a^b+\int\limits_{X}$
$\displaystyle A+\circint_a^b+\circint\limits_{X}$
$A+\circint_a^b+\circint_X$
$\scriptstyle A+\circint_a^b+\circint_X$
\end{document}
答案2
这是一个更简单的替代方案:
\documentclass{article}
\usepackage{amsmath}
\makeatletter
\DeclareMathOperator{\circint}{
\mathchoice%
{\ooalign{$\displaystyle\int$\cr\large$\mkern4mu\mathcal{C}$\cr $\displaystyle\int$}}
{\ooalign{$\int$\cr\scriptsize$\mkern3mu\mathcal{C}$\cr $\int$}}
{\ooalign{$\scriptstyle\int$\cr\tiny$\mkern2mu\mathcal{C}$\cr $\scriptstyle\int$}}
{\ooalign{$\scriptscriptstyle\int$\cr\tiny$\mathcal{C}$\cr $\scriptscriptstyle\int$}}
}
\makeatother
\begin{document}
\(_{_{\circint_{-\infty}^{\infty} f(x)\,dx+\int_{-\infty}^{\infty} f(x)\,dx}}\)
\(_{\circint_{-\infty}^{\infty} f(x)\,dx+\int_{-\infty}^{\infty} f(x)\,dx}\)
\(\circint_{-\infty}^{\infty} f(x)\,dx+\int_{-\infty}^{\infty} f(x)\,dx\)
\(\displaystyle\circint_{-\infty}^{\infty} f(x)\,dx+\int_{-\infty}^{\infty} f(x)\,dx\)
\end{document}