8

I wish to write X as product like $X_{n=1}^k$. How to write it? For example, we write $\sum \limits _{n=1}^k$

LaRiFaRi
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6-0
  • 217
  • 1
    Welcome to TeX.SX! I am not sure if I get you right. Please explain a bit more, what you want to achieve here. If necessary draw a little picture and post it. Do you want to get a new symbol which is used like \prod \limits but looks like a big X? – LaRiFaRi Sep 22 '14 at 11:09
  • I wish to write \times but a bit larger with limits. – 6-0 Sep 22 '14 at 11:11
  • Welcome to TeX.SX! You can have a look at our starter guide to familiarize yourself further with our format. – Martin Schröder Sep 22 '14 at 11:19
  • There are several related posts: http://tex.stackexchange.com/search?q=bigtimes – egreg Sep 22 '14 at 12:37

3 Answers3

12

Classical TeX

Both MnSymbol and mathabx provides the symbol \bigtimes. However both packages also change the math symbols, but it is also possible to only get \bigtimes.

MnSymbol

\documentclass{article}
\usepackage{MnSymbol}

\begin{document}
\[
  \bigtimes_{n=1}^k
\]
\end{document}

Result MnSybmol

Version without package MnSymbol by using the relevant code from the package only:

\documentclass{article}

% MnSymbol

\usepackage{amsmath}% provides \DOTSB and \slimits@
\makeatletter
\DeclareFontFamily{U}  {MnSymbolF}{}
\DeclareSymbolFont{symbolsMN}{U}{MnSymbolF}{m}{n}
\SetSymbolFont{symbolsMN}{bold}{U}{MnSymbolF}{b}{n}
\DeclareFontShape{U}{MnSymbolF}{m}{n}{
    <-6>  MnSymbolF5
   <6-7>  MnSymbolF6
   <7-8>  MnSymbolF7
   <8-9>  MnSymbolF8
   <9-10> MnSymbolF9
  <10-12> MnSymbolF10
  <12->   MnSymbolF12}{}
\DeclareFontShape{U}{MnSymbolF}{b}{n}{
    <-6>  MnSymbolF-Bold5
   <6-7>  MnSymbolF-Bold6
   <7-8>  MnSymbolF-Bold7
   <8-9>  MnSymbolF-Bold8
   <9-10> MnSymbolF-Bold9
  <10-12> MnSymbolF-Bold10
  <12->   MnSymbolF-Bold12}{}
\DeclareMathSymbol{\tbigtimes}{\mathop}{symbolsMN}{2}
\newcommand*{\bigtimes}{%
  \DOTSB
  \tbigtimes
  \slimits@ 
}
\makeatother

\begin{document}
\[
  \bigtimes_{n=1}^k
\]
\end{document}

mathabx

\documentclass{article}
\usepackage{mathabx}

\begin{document}
\[
  \bigtimes_{n=1}^k
\]
\end{document}

Result mathabx

Without package:

\documentclass{article}

% mathabx

\DeclareFontFamily{U}{mathx}{\hyphenchar\font45}
\DeclareFontShape{U}{mathx}{m}{n}{
      <5> <6> <7> <8> <9> <10>
      <10.95> <12> <14.4> <17.28> <20.74> <24.88>
      mathx10
      }{}
\DeclareSymbolFont{mathx}{U}{mathx}{m}{n}
\DeclareFontSubstitution{U}{mathx}{m}{n}
\DeclareMathSymbol{\bigtimes}{1}{mathx}{"91}

\begin{document}
\[
  \bigtimes_{n=1}^k
\]
\end{document}

LuaTeX/XeTeX with unicode-math

As David Carlisle has written in his answer, the symbol is a Unicode symbol:

U+2A09 n-ary times operator

It can be used directly or via command \bigtimes with package unicode-math and TeX engines, which support OpenType fonts (LuaTeX, XeTeX).

Example with different fonts:

\documentclass[fleqn]{article}

\usepackage{unicode-math}

\begin{document}
  \newcommand*{\test}[1]{%
    \setmathfont{#1.otf}%
    \[
      \bigtimes_{n=1}^k\quad \mbox{\footnotesize(#1)}%
    \]%
  }
  \test{latinmodern-math}
  \test{Asana-Math}
  \test{xits-math}
  \test{texgyrebonum-math}
  \test{texgyrepagella-math}
  \test{texgyreschola-math}
  \test{texgyretermes-math}
\end{document}

Result unicode-math

Community
  • 1
Heiko Oberdiek
  • 271,626
7

Is this what you mean? Here are two variants, using answer from How are big operators defined?

\documentclass{article}
\usepackage{amsmath}
\usepackage{amsfonts}
\DeclareMathOperator*{\foo}{\scalerel*{\times}{\sum}}
\DeclareMathOperator*{\barr}{\scalerel*{\times}{\textstyle\sum}}
\usepackage{scalerel}

\begin{document}
\[
\foo_{i=3}^{6}(f^2(i))
\]

This is inline: \(\foo_{i=3}^{6}(f^2(i)) \)

\[
\barr_{i=3}^{6}(f^2(i))
\]

This is inline: \(\barr_{i=3}^{6}(f^2(i)) \)
\end{document}

enter image description here

Community
  • 1
Steven B. Segletes
  • 237,551
  • It,s not like "\times". It is like "X". I want to write like "\times" with limits. – 6-0 Sep 22 '14 at 11:13
  • @hamed Please see revision – Steven B. Segletes Sep 22 '14 at 11:14
  • The spacing isn't right here; there's too much horizontal space around the symbol (e.g. look at the location of the arguments when you call the command inline; there's a big space separating the X from the subscript "i=3" and the superscript 6.). – xFioraMstr18 Nov 05 '21 at 16:03
  • To fix the spacing issue, this modification of your answer works decently well: \DeclareMathOperator{\bigtimes}{\scalerel{\hspace{-0.09em}\times\hspace{-0.09em}}{\sum}} – xFioraMstr18 Nov 05 '21 at 16:14
  • Thank you @xFioraMstr18. It is true that with the scale, the sidebearing is also scaled, which is normally not called for. Removing some via negative kern seems appropriate. – Steven B. Segletes Nov 05 '21 at 16:31
3

Unicode has this symbol as U+2A09 (⨉) so if you are using a unicode engine (xetex or luatex) you can use that symbol directly or use \bigtimes with unicode-math package. See Heiko's answer to access fonts for classic TeX that have this symbol..

David Carlisle
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