LaTeX Getting Equations Into a Post - A PF Guide

[Old Guy]

Can somebody please explain to me how to get equations into a post? I've read a lot about a sigma symbol that opens some kind of latex thing, but I've not seen the sigma anywhere. I actually use Mathtype a lot (in Word) and it has the capability to translate to various flavors of latex - I'd really prefer to do it in Mathtype and paste it into a post, but if I need to learn another way I'm willing to do so - PF is great! Thanks for help on this - I really did search around before posting this.

 

[Greg Bernhardt]

The LaTeX editor is the sigma symbol next to the TV (youtube) icon in the post editor.

 

[Gokul43201]

See also: https://www.physicsforums.com/showthread.php?t=8997

 

[jtbell]

I actually use Mathtype a lot (in Word) and it has the capability to translate to various flavors of latex - I'd really prefer to do it in Mathtype and paste it into a post,

Set your MathType preferences to export to LaTeX 2.09, and turn off "Include MathType data in translation." Then when you copy from MathType and paste into the PF message-editing window, you should get LaTeX code. I got "\[" before and "\]" after the equation; if you get them, too, delete them. Insert a [ tex ] tag before and a [ /tex ] tag after the equation (remove the spaces inside the brackets... I had to put them there so PF wouldn't interpret them as tags). That's how I did the equation below.

<br /> \sqrt {a^2 + b^2 } <br />

For most equations it's quicker for me to type the LaTeX by hand, but for complicated stuff I sometimes use MathType instead.

 

[EduardoT]

Set your MathType preferences to export to LaTeX 2.09, and turn off "Include MathType data in translation." Then when you copy from MathType and paste into the PF message-editing window, you should get LaTeX code. I got "\[" before and "\]" after the equation; if you get them, too, delete them. Insert a [ tex ] tag before and a [ /tex ] tag after the equation ...

You can avoid having to replace the delimiters (the [ tex ] for "\[" , [ /tex ] for "\]") by hand each time if you create your own MathType translator file.

For that you would have to:

1. Copy the file "LaTeX.tdl" from MathType's translators directory (in Windows, it is "C:\Program Files\MathType\Translators" by default). Let's say you call this copy "FPLatex.tdl"
2. Edit this new FPLatex.tdl translator file, and in the line that starts with "eqn = " replace "\["with "&quot;and &quot;\]&quot; with &quot;[ /tex ]&quot; (take out the spaces after and before the brackets.)<br /> It should look like this:<br /> eqn = &quot;&lt;StdStartCmt&gt;&lt;EqnDataCmt&gt;[ tex ]@n#@n[ /tex ]@n&lt;StdEndCmt&gt;&quot;;<br /> (again, without the spaces inside the square brackets)<br /> [*]Select this translator instead of the LaTeX one for export in MathType.<br />

<br /> <br /> After doing the above (and you only need to do it once) when you copy an equation from MathType it will be ready for pasting in the forum message.

 

[jtbell]

Thanks for the tip! Under Mac OS X, the *.tdl files are in Applications --> MathType 6 --> Translators. (or "MathType 5" or maybe something else depending on which version you're using)

To get the new tdl file to appear as a new item in the Preferences --> Translators menu, you have to edit the first line of the new tdl file so it contains a unique description. I now have a PFLaTeX.tdl file that starts with

MathType Output Translator 1.0: "PF LaTeX", "LaTeX for Physics Forums"

It appears in my Translators menu as "PF LaTeX".

<br /> - \frac{{\hbar ^2 }}{{2m}}\nabla ^2 \Psi + V\Psi = i\hbar \frac{{\partial \Psi }}{{\partial t}}<br />

 

[Redbelly98]

If you're using the "Quick Reply" box to make a post, you'll need to click the "Go Advanced" button to see the special editing symbols. The Σ symbol appears on the far right end of all the symbols.

There's also a limited number of math symbols that you can copy-and-paste into posts:
https://www.physicsforums.com/blog.php?b=347

 

[Old Guy]

Well, I'm back at this again. I've tried EduardoT's suggestion, I've checked the code carefully, I don't get any error messages on the translations, but this is what I get:
$\sqrt {x^2 + y^2 } $
which should be coming out as:
\sqrt {x^2 + y^2}
Any thoughts on how I can fix this?

Also, I don't have a sigma button on my message editor; I've attached a screenshot. Ayn help would be appreciated!

 

[Greg Bernhardt]

Also, I don't have a sigma button on my message editor; I've attached a screenshot. Ayn help would be appreciated!

only displayed in the technical forums

 

[Old Guy]

Ahh . . . thanks Greg. That explains one issue!

 

[EduardoT]

[..] this is what I get:
$\sqrt {x^2 + y^2 } $
which should be coming out as:
[ tex ]\sqrt {x^2 + y^2} [ /tex ]
Any thoughts on how I can fix this?

Check that the new translator you created has them in the rule for eqn, and make sure that you have this new translator selected when copying the equation in MathType.

One thing I neglected, that jtbell metioned afterwards, is that you also want to modify the first line of the translator file, to read something like
MathType Output Translator 1.0: "PF LaTeX", "LaTeX for Physics Forums"
so that it shows in the translators pull down list as "PF LaTeX".

To select a translator in MathType, go to Preferences -> Translators... menu, check "Translation to other language", select the translator from the drop-down list, and click OK.