how does posting math notation work? - Page 1
Forum section: electronics / beginners

author: Simon
author_rank: Unknown
timestamp: October 10, 2020, 08:26:15 am
content: I'd like to post a question with a math formula. I think there is a way of doing it but see no instructions.

author: IanB
author_rank: Super Contributor
timestamp: October 10, 2020, 08:33:13 am
content: Go to MathJax sandbox to get your syntax right, for example like this:http://jbergknoff.github.io/mathjax-sandbox/#JCRjPVxzcXJ0e2FeMitiXjJ9JCQ%3DThen paste the formula into your post surrounded by double dollar signs:$$c=\sqrt{a^2+b^2}$$The reason for using the sandbox is that preview doesn't work in the editor here, so you need to use an external tool to see what your formulas will look like before posting.

author: Simon
author_rank: Unknown
timestamp: October 10, 2020, 08:34:25 am
content: Thank you.

author: Simon
author_rank: Unknown
timestamp: October 10, 2020, 08:35:24 am
content: But is there a list of notation codes somewhere? as it is I use two programs with different methods of doing the same thing, I am sure this will be a third.

author: IanB
author_rank: Super Contributor
timestamp: October 10, 2020, 08:38:57 am
content: It's basically LaTeX math notation. I usually Google that to find tutorials and crib sheets.

author: Simon
author_rank: Unknown
timestamp: October 10, 2020, 08:41:31 am
content: Ah OK, now I know what to google:https://oeis.org/wiki/List_of_LaTeX_mathematical_symbolsIt's certainly not responding to the keywords that open office uses.

author: IanB
author_rank: Super Contributor
timestamp: October 10, 2020, 08:45:01 am
content: This seems to be a good reference:https://en.wikibooks.org/wiki/LaTeX/Mathematics

author: Simon
author_rank: Unknown
timestamp: October 10, 2020, 08:48:02 am
content: It's the long fraction line that seems to be missing, i think I have to use an over line on the denominatorNo it's a \frac:$$ \frac {3-2s} {s^2-4s+9}$$

author: IanB
author_rank: Super Contributor
timestamp: October 10, 2020, 09:09:22 am
content: You can do it either way. For example, this will work too:Code:{3-2s}\over{s^2-4s+9}$${3-2s}\over{s^2-4s+9}$$

author: Simon
author_rank: Unknown
timestamp: October 10, 2020, 09:11:03 am
content: Ah, that is what I was hoping but did not see it. in Libre office you just write "over"

author: Ian.M
author_rank: Super Contributor
timestamp: October 10, 2020, 10:50:29 am
content: Mathjax 2.7 documentation:http://docs.mathjax.org/en/v2.7-latest/The original thread where Dave decided to enable Mathjax:https://www.eevblog.com/forum/suggestions/latex-for-eevblog/

author: Doctorandus_P
author_rank: Super Contributor
timestamp: October 12, 2020, 11:31:39 am
content: Write it on a piece of paper.Make a picture of it.Post it.

author: mathsquid
author_rank: Frequent Contributor
timestamp: October 13, 2020, 02:41:19 am
content: So just put latex code in here and it works?$$\sum_{n=1}^\infty \frac{1}{n^2} = \frac{\pi^2}{6}$$Edit: Sweet.

author: dnwheeler
author_rank: Regular Contributor
timestamp: October 13, 2020, 09:50:08 pm
content: \over and \frac are not equivalent. There is even a visible difference in the examples above.

author: IanB
author_rank: Super Contributor
timestamp: October 14, 2020, 02:58:53 pm
content: Quote from: dnwheeler on October 13, 2020, 09:50:08 pmUsing \frac:$$\frac{3-2s}{s^2-4s+9}$$Using \over:$${3-2s}\over{s^2-4s+9}$$I don't see any difference. How are they different?

author: dnwheeler
author_rank: Regular Contributor
timestamp: October 14, 2020, 08:31:54 pm
content: Interesting. It appears to be some sort of rendering issue. In the previous posts, the "frac" line is clearly 1 pixel higher than the "over" line. In your post, they look the same, but as I'm typing this, the copy of your message shown below the editor shows the "over" line 1 pixel higher.FWIW, I see the same behavior on the Chromium version of Edge and with Chrome (on a Windows 10 system).There are other technical differences discussed here:https://tex.stackexchange.com/questions/73822/what-is-the-difference-between-over-and-frac

author: IanB
author_rank: Super Contributor
timestamp: October 14, 2020, 09:22:40 pm
content: So it's a case of \over being a TeX primitive whereas \frac is a LaTeX macro with more robust behavior?However, I am with Knuth who apparently said that \over is a more natural syntax for mathematicians. As long as I see \over rendering properly it is the one I would prefer to use. I find \frac more awkward as it doesn't support a linear thought process when writing equations.Edit: apparently \frac also uses a form of \over internally when it expands the macro.

author: RoGeorge
author_rank: Super Contributor
timestamp: October 14, 2020, 09:35:25 pm
content: Enclose the formula between backslash dollar if you need an inline formula, for example like this one \$\Phi = BA\$, placed in a normal conversation.Sometimes I usehttps://www.codecogs.com/latex/eqneditor.phpas an online editor, good to see the rendered formula, because the forum shows the rendered formula only after posting, it does not render it at preview.LATER EDIT: Found an older post with a clean example in it.Latex enclosed by backslash dollar will render it inline, when enclosed by double dollar will render centered, on a new line.Example:Code:From Faraday's induction law, the induced voltage \$V\$ in an \$N\$ turns coil will be:$$V = -N\frac{\vartriangle \Phi}{\vartriangle t}$$where \$\Phi\$ is the magnetic fluxFrom Faraday's induction law, the induced voltage \$V\$ in an \$N\$ turns coil will be:$$V = -N\frac{\vartriangle \Phi}{\vartriangle t}$$where \$\Phi\$ is the magnetic fluxThe Latex render will be seen only after posting the message, not at preview.

author: RoGeorge
author_rank: Super Contributor
timestamp: October 14, 2020, 09:57:31 pm
content: Code:Trying a new one\[\vartheta=2\pi \tag{5.5} \label{eq:best}\]Space between consecutive formulae\[\mathbf{A}\textbf{B} \tag{5.6} \label{eq:special}\]A reference to eq. \eqref{eq:best} and a cross-reference to \eqref{eq:special}.Trying a new one\[\vartheta=2\pi \tag{5.5} \label{eq:best}\]Space between consecutive formulae\[\mathbf{A}\textbf{B} \tag{5.6} \label{eq:special}\]A reference to eq. \eqref{eq:best} and a cross-reference to \eqref{eq:special}.

author: Andy Watson
author_rank: Super Contributor
timestamp: October 14, 2020, 10:35:53 pm
content: And can I reference a previous post. Like equation \eqref{eq:best} ?Apparently I can !

author: wizard69
author_rank: Super Contributor
timestamp: October 16, 2020, 04:45:22 am
content: Interesting thread as i never considered math posting here. Sadly this doesn't work on an Iphone with MathML turned on. Not sure what is going on there but it works fine on Firefox on Linux

author: Cerebus
author_rank: Super Contributor
timestamp: October 18, 2020, 11:31:22 pm
content: Quote from: wizard69 on October 16, 2020, 04:45:22 amYeah, it does, it's just that the site is noticing you're on a phone and serving a 'phone' version of the site. Go to the bottom of the page, select 'menu' and then 'full site'.

author: Terry Bites
author_rank: Super Contributor
timestamp: January 08, 2021, 02:21:08 pm
content: of course you can just do a screen shot and stick it in as an image

author: Cerebus
author_rank: Super Contributor
timestamp: January 08, 2021, 02:26:21 pm
content: Quote from: Terry Bites on January 08, 2021, 02:21:08 pmI can see how that would appeal to someone for whom full stops and starting a sentence with a capital letter seems too onerous.

author: TimFox
author_rank: Super Contributor
timestamp: January 14, 2021, 08:17:16 pm
content: I normally use the equation editor in Microsoft Word to generate equations to be included in Word documents.Is there a simple way to include such an equation into a post here?

author: Cerebus
author_rank: Super Contributor
timestamp: January 14, 2021, 08:37:11 pm
content: Quote from: TimFox on January 14, 2021, 08:17:16 pmSeeherefor details of Word's \$\LaTeX\$ math mode capabilities in the equation editor. There's an embedded video on how to get \$\LaTeX\$ out of the equation editor.

author: Xandinator
author_rank: Contributor
timestamp: December 19, 2021, 12:33:17 pm
content: OpenOffice.org/LibreOffice/... users can use the Math editor and export to MathML when using "Save As". From there you can choose a number of options.

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 22, 2022, 07:31:30 pm
content: For those using wxMaxima, you can select any expression, right click and use "Copy as LaTeX". Then paste.\[\frac{\cos{(x)}}{x}-\frac{\sin{(x)}}{{{x}^{2}}}\]Note that it won't be displayed WYSIWYG in preview mode, which is annoying.

author: RoGeorge
author_rank: Super Contributor
timestamp: February 08, 2022, 01:54:44 pm
content: (MathJax == LaTex like syntax)The best brief MathJax tutorial:https://math.meta.stackexchange.com/questions/5020/mathjax-basic-tutorial-and-quick-referenceRandom demo from the above link examples:Code:\$\require{AMScd} \require{cancel}\$\begin{CD}A @>a>> \mathrm{ \color{red}{AC \unicode{x21af} DC} \impliedby \overline{ \xcancel{not} ITALIC} }\\@V b V V{f(n) =\begin{cases}\sum_{i=1}^n i^2 = \frac{n(n+1)(2n+1)}{6}, & \text{if $n$ is even} \\3n+1, & \text{if $n$ is odd}\end{cases}}@VV c V\\e^{i\pi/2} @>>d> {\mu_0=4\pi\times10^{-7} \ \left.\mathrm{\mathrm{T}\!\cdot\!\mathrm{m}}\middle/\mathrm{A}\right.}\end{CD}\$\require{AMScd} \require{cancel}\$\begin{CD}A @>a>> \mathrm{ \color{red}{AC \unicode{x21af} DC} \impliedby \overline{ \xcancel{not} ITALIC} }\\@V b V V{f(n) =\begin{cases}\sum_{i=1}^n i^2 = \frac{n(n+1)(2n+1)}{6}, & \text{if $n$ is even} \\3n+1, & \text{if $n$ is odd}\end{cases}}@VV c V\\e^{i\pi/2} @>>d> {\mu_0=4\pi\times10^{-7} \ \left.\mathrm{\mathrm{T}\!\cdot\!\mathrm{m}}\middle/\mathrm{A}\right.}\end{CD}Code:\[ \star \ \star \ \star \]Normal \$ \unicode{x23fb} \ \unicode{x238d} \ \unicode{x23da} \ \unicode{x23fc} \ \$ text.\[ \star \ \star \ \star \]Normal \$ \unicode{x23fb} \ \unicode{x238d} \ \unicode{x23da} \ \unicode{x23fc} \ \$ text.

author: radiolistener
author_rank: Super Contributor
timestamp: November 25, 2023, 05:43:15 pm
content: test \$\sqrt[\pi]{\pi^\pi}=\pi\$

author: lu1s.p
author_rank: Contributor
timestamp: February 18, 2025, 08:14:43 am
content: Thanks for this advice,I have the same problem too