[Tex/LaTex] LaTeX symbol for a particular chi-squared

symbols

In the book An Introduction to Error Analysis: The Study of Uncertainties in Physical Measurements by J. R.Taylor I find the following formula:

enter image description here

In LaTeX, does it exist any symbol for enter image description here shown above?

Best Answer

% arara: pdflatex

\documentclass{article}

\begin{document}
\[\tilde{\chi}^2=\frac{1}{d}\sum_{k=1}^{n} \frac{(O_k - E_k)^2}{E_k}\]
\end{document}

enter image description here

Related Solutions

[Tex/LaTex] Looking for symbol: Shield

You could, of course, use TikZ for this:

The symbol will scale with your font size, since it uses ex to define the path.

\documentclass{article}
\usepackage{tikz}
\begin{document}
\newcommand\shield{%
    \tikz [baseline] \draw (0,1.75ex) -- (0,0.75ex) arc [radius=0.75ex, start angle=-180, end angle=0] -- (1.5ex,1.75ex) -- cycle;%
}

A shield: \shield
\end{document}

If you're feeling fancy, you could parametrise it a bit:

\documentclass[border=3mm]{standalone}
\usepackage{tikz}
\begin{document}
\newcommand\shield[1][]{%
\tikzset{
    shield width/.store in=\shieldwidth,
    shield width=1.5ex,
    shield height/.store in=\shieldheight,
    shield height=1.75ex
}%
\tikz [baseline,#1] \draw (0,\shieldheight) -- (0,\shieldwidth/2) arc [radius=\shieldwidth/2, start angle=-180, end angle=0] -- (\shieldwidth,\shieldheight) -- cycle;%
}

A shield: \shield

A wide shield: \shield[shield width=2ex]

A tall shield: \shield[shield height=3ex]
\end{document}

[Tex/LaTex] LaTeX command for unknown symbol

The following example constructs the symbol in the following way:

The top part with the round line end of the vertical bar is used as branch line.
The length of the branch is the same as in the plus symbol. But the length can be changed by redefining \UpDownYFactor to a value different than 1.
The intersection point is the same as in the plus symbol at the mathematical center axis.
The symbol adopts in size to the current math style.
The side bearings have the same width as in the plus symbol.
The names for the provided symbols are the same as in package MnSymbol: \upY and \downY.
The symbols act as binary operators. It can be changed by replacing \mathbin.

Example file:

\documentclass{article}
\usepackage{graphicx}
\usepackage{trimclip}

\makeatletter
\providecommand*{\upY}{%
  \mathbin{%
    \mathpalette\@updownY{0}%
  }%
}
\providecommand*{\downY}{%
  \mathbin{%
    \mathpalette\@updownY{1}%
  }%
}
\providecommand*{\UpDownYFactor}{1}
\newcommand*{\@updownY}[2]{%
  % #1: math style
  % #2: 0 = up, 1 = down
  \sbox0{$#1+\m@th$}%
  \dimen2=.5\dimexpr\wd0-\ht0-\dp0\relax
  % => \dimen2: side bearing
  \sbox2{$#1\vcenter{}$}%
  \dimen4=\dimexpr\ht0-\ht2\relax
  % => \dimen4: branch length
  \setbox0=\hbox to 0pt{%
    \hss
    \clipbox{%
      0pt %
      {\dimexpr\totalheight-\UpDownYFactor\dimen4\relax} %
      0pt %
      -\dimen2%
    }{$#1|$}%
    \hss
  }%
  \ht0=\dimexpr\ht0-\dimen2\relax
  \kern\dimen2 %
  \raise\ht2\hbox{%
    \ifnum#2=0 %
      {\rotatebox{120}{\copy0}}%
      \copy0 %
      {\rotatebox{-120}{\copy0}}%
    \else
      {\rotatebox{60}{\copy0}}%
      {\rotatebox{180}{\copy0}}%
      {\rotatebox{-60}{\copy0}}%
    \fi
  }%
  \kern\dimen2 %
}
\makeatother

\begin{document}
\[\begin{array}{c}
  a \upY b \downY c
  \\
  \scriptstyle
  a \upY b \downY c
  \\
  \scriptscriptstyle
  a \upY b \downY c
  \\
  \rlap{$\upY$}{\downY}
\end{array}\]
\end{document}

For analyzing the center:

\usepackage{pdfrender}
...
\[
  \rlap{%  
    \sbox0{$\vcenter{}$}%
    \sbox2{${\upY}{\downY}{\upY}$}%
    \raise\ht0\hbox{\vrule height.01pt depth.01pt width\wd2}%
  }%
  \pdfrender{TextRenderingMode=Stroke, LineWidth=.01pt}
  {\upY}\rlap{$\upY$}{\downY}{\downY}
\]

Best Answer

Related Solutions

[Tex/LaTex] Looking for symbol: Shield

[Tex/LaTex] LaTeX command for unknown symbol

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