[Tex/LaTex] How to write the “estimate” equal sign

Question

I'm looking for a code, which can depict the estimate equal sign as in http://en.wikipedia.org/wiki/Equals_sign#Other_related_symbols (6th sign: ESTIMATES).

Answer 1

The following summarizes many variants of the estimate symbol without changing all math symbols.

\newcommand*{\estimatesA}{\mathrel{\hat=}}

Source: Bernard's answer, Johannes_B's comment

\newcommand*{\estimatesB}{\mathrel{\widehat=}}

Source: DanteFAQ, Bernard's answer

\newcommand*{\estimatesC}{\stackrel{\scriptscriptstyle\wedge}{=}}

Source: DanteFAQ
Remark: Recommended for \displaystyle and \textstyle only, in the smaller styles, the \wedge becomes too large.

\newcommand*{\estimatesD}{\hateq} % MnSymbol

Source: Jukka K. Korpela's answer

\newcommand*{\estimatesE}{\corresponds} % mathabx

Source: The Comprehensive LaTeX Symbol List

\newcommand*{\estimatesF}{\mathrel{\text{\Corresponds}}} % marvosym

Source: Ian Thompson's comment

---

\documentclass{article}

\newcommand*{\estimatesA}{\mathrel{\hat=}}
\newcommand*{\estimatesB}{\mathrel{\widehat=}}
\newcommand*{\estimatesC}{\stackrel{\scriptscriptstyle\wedge}{=}}
\newcommand*{\estimatesD}{\hateq} % MnSymbol
\newcommand*{\estimatesE}{\corresponds} % mathabx
\newcommand*{\estimatesF}{\mathrel{\text{\Corresponds}}} % marvosym

\usepackage{marvosym,amstext}

\makeatletter

% \hateq from MnSymbol
% \usepackage{MnSymbol}
\@ifpackageloaded{MnSymbol}\@tempswafalse\@tempswatrue
\if@tempswa
  \DeclareFontFamily{U}{MnSymbolD}{}%
  \DeclareSymbolFont{MnSyD}{U}{MnSymbolD}{m}{n}%
  \SetSymbolFont{MnSyD}{bold}{U}{MnSymbolD}{b}{n}%
  \DeclareFontShape{U}{MnSymbolD}{m}{n}{
      <-6>  MnSymbolD5
     <6-7>  MnSymbolD6
     <7-8>  MnSymbolD7
     <8-9>  MnSymbolD8
     <9-10> MnSymbolD9
    <10-12> MnSymbolD10
    <12->   MnSymbolD12}{}%
  \DeclareFontShape{U}{MnSymbolD}{b}{n}{
      <-6>  MnSymbolD-Bold5
     <6-7>  MnSymbolD-Bold6
     <7-8>  MnSymbolD-Bold7
     <8-9>  MnSymbolD-Bold8
     <9-10> MnSymbolD-Bold9
    <10-12> MnSymbolD-Bold10
    <12->   MnSymbolD-Bold12}{}%
  \DeclareMathSymbol{\hateq}{\mathrel}{MnSyD}{61}% 
\fi

% \corresponds from mathabx
% \usepackage{mathabx}
\@ifpackageloaded{mathabx}\@tempswafalse\@tempswatrue
\if@tempswa
  \DeclareFontFamily{U}{mathb}{\hyphenchar\font45}%
  \DeclareFontShape{U}{mathb}{m}{n}{
        <5> <6> <7> <8> <9> <10> gen * mathb
        <10.95> mathb10 <12> <14.4> <17.28> <20.74> <24.88> mathb12
        }{}%
  \DeclareSymbolFont{mathb}{U}{mathb}{m}{n}%
  \DeclareFontSubstitution{U}{mathb}{m}{n}%
  \DeclareMathSymbol{\corresponds}{\mathrel}{mathb}{"1D}%
\fi
\makeatother

\begin{document}
\[
  A \estimatesA
  B \estimatesB
  C \estimatesC
  D \estimatesD
  E \estimatesE
  F \estimatesF
  G
\]
\end{document}

OpenType fonts

LuaTeX and XeTeX support OpenType fonts. Package unicode-math supports OpenType math fonts. The symbol ≙ can then be used in different ways:

• Direct in put of the Unicode symbol: ≙
• ASCII notation of the symbol: ^^^^2259
• Command name (package unicode-math): \wedgeq

The following example shows the symbols from three OpenType math fonts (Family name/PostScript name/font name):

• Latin Modern Math/LatinModernMath-Regular/latinmodern-math.otf
• Asana Math/Asana-Math/Asana-Math.otf
• XITS Math/XITSMath/xits-math.otf

\documentclass{article}

\usepackage{unicode-math}

\AtBeginDocument{%
  \setmathfont{latinmodern-math.otf}%
  \newsavebox\BoxG\sbox\BoxG{$\wedgeq$}%
  %
  \setmathfont{Asana-Math.otf}%
  \newsavebox\BoxH\sbox\BoxH{$\wedgeq$}%
  %
  \setmathfont{xits-math.otf}%
  \newsavebox\BoxI\sbox\BoxI{$\wedgeq$}%
  %
  \setmathfont{latinmodern-math.otf}%
}

\newcommand*{\test}[1]{\mathrel{\copy#1}}

\begin{document}
\[
  G \test\BoxG
  H \test\BoxH
  I \test\BoxI
  J
\]
\end{document}