# 3 dots in matrix

I was wondering if anyone knew how to draw 3 dots in a matrix that go in a diagonal way usually to represent that element flow similarily in the slots. I know there's one that goes in the bottom right corner. But is there one that goes in the bottom left?

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## migrated from math.stackexchange.comOct 21 '11 at 5:39

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Welcome to TeX.sx! Your question was migrated here from Math StackExchange site. Please register on this site, too, and make sure that both accounts are associated with each other, otherwise you won't be able to comment on or accept answers or edit your question. –  Werner Oct 21 '11 at 5:51
This might be useful: How to look up a math symbol –  cmhughes Oct 21 '11 at 5:53
@cmhughes: Interestingly enough, Detexify was my first stop after the Comprehensive LaTeX symbol list, and it was unable to give me any meaningful output. –  Werner Oct 21 '11 at 6:01
@Werner: If I draw three dots, Detexify presents me with horizontal results, but clicking on "Select from the complete list" shows \iddots fairly high on the list. –  Jake Oct 21 '11 at 6:20
@Jake: Argh... I didn't view the "complete list", that was my problem. –  Werner Oct 21 '11 at 6:21

The MnSymbol package provides \udots that prints 3 dots going from NE to SW; in the opposite direction of \ddots which goes from NW to SE.

Similar dots are provided by \iddots from mathdots and \adots from yhmath. See p 60 of the Comprehensive LaTeX symbol list. You could also use \reflectbox{<stuff>} from the graphicx package to reflect something about the vertical axis.

Here's a brief overview:

\documentclass{article}
\usepackage{graphicx}% http://ctan.org/pkg/graphicx
\usepackage{yhmath}% http://ctan.org/pkg/yhmath
\usepackage{mathdots}% http://ctan.org/pkg/mathdots
\usepackage{MnSymbol}% http://ctan.org/pkg/mnsymbol
\begin{document}
Different versions of diagonal dots:

$\renewcommand{\arraystretch}{1.5}% \begin{array}{ll} \verb!\ddots! & \ddots \\ \verb!\udots! & \udots \\ \verb!\iddots! & \iddots \\ \verb!\adots! & \adots \\ \verb!\reflectbox{$\ddots$}! & \reflectbox{$\ddots$} \end{array}$
\end{document}

In addition to the above source of LaTeX symbols, Detexify is also a fast way to identify symbols in LaTeX. Remember to "Select from the complete list!" if you don't see your symbol immediately, since the scoring algorithm may be off, depending on the symbol (or one's drawing prowess).

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Do not use MnSymbol if you don't want to change the math fonts globally. MnSymbol is often overused. And note that yhmath is mainly designed for CM (or LM) fonts. mathdots and yhmath are both acceptble in most cases. –  Leo Liu Oct 21 '11 at 7:01
\ddots doesn't need any packages. Nor does \vdots –  Seamus Oct 21 '11 at 7:18
@LeoLiu: Is it necessary to change math fonts globally in order to use the mnsymbol package? That's not something I've experienced so far... –  Mico Oct 21 '11 at 19:35
@Mico: It is a little strange to use it with CM/LM fonts. This is explained at the beginning of the document of mnsymbol: “MnSymbol is a font of mathematical symbols designed as companion to Adobe MinionPro, but it might also fit well to other renaissance or baroque faces.” –  Leo Liu Oct 22 '11 at 3:30

For a good source to math symbols, I think the Comprehensive LaTeX symbol list is a complement to the very good document Mathmode.pdf. This document is interesting because it offers another organisation and you can find all about mathematics.

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