Andreas Leha <andreas.leha@med.uni-goettingen.de> writes:

> Hi Rainer,
>
> Rainer M Krug <Rainer@krugs.de> writes:
>> Hi
>>
>> I would need in a document several equations which are aligned as in 
>> http://tex.stackexchange.com/a/167908/6941
>>
>> How can I use the following latex formula in orgmode?
>>
>> \begin{proof} The proof is a follows: 
>> \begin{align}
>> (x+y)^3&=(x+y)(x+y)^2\\
>>        &=(x+y)(x^2+2xy+y^2)\\
>>        &=x^3+3x^2y+3xy^3+x^3.\qedhere
>> \end{align}
>> \end{proof}
>>
>>
>> I have effectrively
>>
>> #+LATEX_HEADER: \usepackage{amsmath}
>>
>> * The equations
>>
>> \begin{equation}
>> \begin{align}
>> (x+y)^3&=(x+y)(x+y)^2\\
>>        &=(x+y)(x^2+2xy+y^2)\\
>>        &=x^3+3x^2y+3xy^3+x^3.\qedhere
>> \end{align}
>> \end{equation}
>>
>>
>> but with latex fragment preview (C-c C-x C-l) I only get an empty frame.
>>
>> How can use this align environment in org?
>
> This seems to a problem with your setup of preview latex.  It
> should work just fine.

But it doesn't:

- I started emacs with -Q
- executed the following in scratch to load newest org
--8<---------------cut here---------------start------------->8---
;; Load up Org Mode and Org Babel for elisp embedded in Org Mode files
(add-to-list 'load-path "~/.emacs.d/org-mode/lisp")
(add-to-list 'load-path "~/.emacs.d/org-mode/contrib/lisp")

;; load up Org-mode and Org-babel
(require 'org)
--8<---------------cut here---------------end--------------->8---
- pasted this in an org buffer
--8<---------------cut here---------------start------------->8---
#+LaTeX_header: \usepackage{amsmath} %% needed explicitely for org-preview-latex

* General conditions
The general conditions for all parametrizations are the following:

\begin{equation}
     x=\sqrt{b}
\end{equation}

\begin{equation}
\begin{align*}
(x+y)^3&=(x+y)(x+y)^2\\
       &=(x+y)(x^2+2xy+y^2)\\
       &=x^3+3x^2y+3xy^3+x^3.\qedhere
\end{align*}
\end{equation}


\begin{eqnarray*}
\hat{f}(x) & \propto & \sum_{\nu} \frac{|F(\nu)H(\nu)|^2}{|N(\nu)|^2}  
           \frac{G(\nu)}{H(\nu)} e^{\frac{2 \pi i \nu x}{N}}\\
           & \propto & \sum_{\nu} \frac{|F(\nu)|^2}{|N(\nu)|^2} H(\nu) H^*(\nu) 
           \frac{G(\nu)}{H(\nu)} e^{\frac{2 \pi i \nu x}{N}}\\
           & \propto & \sum_{\nu} H^*(\nu) G(\nu) e^{\frac{2 \pi i \nu x}{N}}
\end{eqnarray*}

--8<---------------cut here---------------end--------------->8---

- did C-c C-x C-l (which runs (org-preview-latex-fragment)) on each
formula and I got the attached screenshot [1]