2

Picture:

enter image description here

Question is by far simple, how do I print the sigma greek letter?. Situation is that I want to print it as my teacher write it. As shown in the picture. I already tried Detexify with no success by the way.

12
  • Picture? \sigma?
    – percusse
    Oct 20, 2014 at 22:43
  • possible duplicate of How to look up a symbol or identify a math symbol or character? Oct 20, 2014 at 22:45
  • o_O Which picture? do you mean $\sigma$ or $\varsigma$?
    – Aradnix
    Oct 20, 2014 at 22:45
  • 2
    It's also important as to what purpose. If you're trying to write a sum, there is \sum that has proper spacing. If you're using sigma for something else, there's \Sigma \sigma \varsigma. If you're writing greek texts, there's all sorts of unicode support. Be more specific. Oct 20, 2014 at 22:46
  • 3
    I voted for keeping this open, but you should clarify what you want to get. If your teacher writes sigma that way, it's not necessarily an example to be followed.
    – egreg
    Oct 20, 2014 at 23:29

2 Answers 2

8

I don't recognise the image as a sigma. Unicode has three variant lowercase sigmas

U+03c2 GREEK SMALL LETTER FINAL SIGMA
U+03c3 GREEK SMALL LETTER SIGMA
U+03f2 GREEK LUNATE SIGMA SYMBOL

which look like

ςσϲ

or as an image

enter image description here


If you are convinced you want the letter shape you drew just save it as a png or (better if you can) a scalable format such as pdf, then you can do

enter image description here

\documentclass{article}

\usepackage{graphicx,amsmath}

\newcommand\bentpaperclip{\includegraphics[height=1ex]{bentpaperclip.png}}

\begin{document}

\[\sigma \neq \varsigma \neq \bentpaperclip\]

\end{document}
16
  • @ David Carlisle: For me it's a small (non-final) σ, with some awkwardness due to the fact it's not that easy to make a drawing with a mouse
    – Bernard
    Oct 21, 2014 at 0:07
  • 3
    @Hans Teachers can be wrong:-) But anyway I updated the answer with something you could use. Oct 21, 2014 at 0:35
  • 2
    +1 for \bentpaperclip
    – Manuel
    Oct 21, 2014 at 0:38
  • 1
    @DavidCarlisle Yeah, yeah I know but it would be fantastic what Manuel typed in the comments, a version made in tikz is just that I don't know how to. And I actually needed like $\bentpaperclip_x$ (thanks for the name for the letter by the way I think it fits as hell).
    – Hans
    Oct 21, 2014 at 0:46
  • 1
    @Hans I am greek and David Carlisle is right. The first symbol σ is the sigma that goes inside of the words. The second one ς is the sigma that goes at the end of the words. The sigma that you draw it is my belief that is the first one and not something different because there is not such a letter in the greek alphabet. Your teacher I believe was just in a hurry so that is why it isn't very similar to the ones seen in this answer. Hope that helped!
    – Adam
    Oct 21, 2014 at 2:07
2

After thinking a lot about the situation I found that the best solution wasn't actually import a png version of the character. And also I found that it could be good to have a way to change the character properties.

Best way to solve the question is create the character using Tikz:

\newcommand{\UNALsigma}[1]{%
\scalebox{#1}{
\begin{tikzpicture}%
\draw[thick, fill] (0.7,-0.3)--(0.8,-0.3)--(0.3,-1)--(0,0)--(1,-0.1)--(1,-0.2)--(0.95,-0.1)--(0.1,-0.1)--(0.3,-0.9)--(0.8,-0.3);%
%
\end{tikzpicture}%
}}
\newcommand{\UNALsigmarc}[1]{%
\scalebox{#1}{
\begin{tikzpicture}%
\draw [thick, fill] plot [smooth, tension=0.2] coordinates { (0.7,-0.3) (0.8,-0.3) (0.3,-1) (0,0) (1,-0.1) (1,-0.2) (0.95,-0.1) (0.1,-0.1) (0.3,-0.9) (0.8,-0.3)};
%
\end{tikzpicture}%
}}

In that way when "typing" in the character \UNALsigma{0.4} or \UNALsigmarc, between the brackets the character can be scaled. Also \UNALsigmarc is a "rounded-corners" version of the character. The output is the following: \UNALsigma{0.4} \UNALsigmarc{0.4}

Also the character is usable in mathmode:

\begin{align*}
\UNALsigmarc{0.35}=\frac{P}{A}
\end{align*}

Obtaining: Mathmode \UNALsimgarc

Also roundness is customizable by changing the smooth tension in the plot of the character.

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  • 4
    Of course nobody will understand the symbol.
    – egreg
    Feb 8, 2015 at 17:43
  • To me it looks like a handwritten \nabla.
    – Manuel
    Feb 8, 2015 at 17:45
  • If you're really going to go this route, at least use some font-relative unit like ex or em instead of cm which has absolutely no hope of scaling automatically with the font size. Feb 8, 2015 at 18:11
  • @egreg Thank you so much for participating with such a useful comment. By the way I actually persisted creating the symbol because I realize all the mechanics and mechatronics department in my university DO use the symbol.
    – Hans
    Feb 9, 2015 at 19:48
  • @Manuel Yeah is sort of similar, thanks for the comment (it isn't nabla if that is maybe what you meant, is sigma character for stress).
    – Hans
    Feb 9, 2015 at 19:50

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