[Tex/LaTex] Package amsmath Error: Erroneous nesting of equation structures

alignamsmathpandoc

When I run pandoc periodic.md -o example.pdf --pdf-engine=xelatex --template eisvogel --listings -VCJKmainfont="Microsoft YaHei", pandoc reported an error:

! Package amsmath Error: Erroneous nesting of equation structures;
(amsmath)                trying to recover with `aligned'.

See the amsmath package documentation for explanation.
Type  H <return>  for immediate help.
 ...

l.430 \end{align}

BTW, I use pandoc-latex-template so there is --template eisvogel in the command.

Here's my markdown source file.
Actually, this document is written in another language and this is the reason why there is -VCJKmainfont="Microsoft YaHei" in the command I executed. For easy understanding, I translate it into English.

---
title: "Cyclical phenomena in life"
author: [andylizf]
date: "2019.3.23"
keywords: [Markdown]
---


## Definition of periodicity

In general, for the function $f(x)$, if there is a non-zero constant $T$, such that for every $x$ in the domain,
$$
f(x + T) = f(x)
$$
For a periodic function $f(x)$, if there is a smallest positive number in all its cycles, then this smallest positive number is called the smallest positive period of $f(x)$.

## Periodic phenomena in mathematics

### Trigonometric function

According to the induction formula,
$$
\begin{align}
    \sin x&= \sin(x + 2\pi) \label{eq1}\\
    \cos x&= \cos(x + 2\pi) \label{eq2}\\
    \tan x&= \tan(x + \pi) \label{eq3}\\
\end{align}
$$

Best Answer

The {align} or {align*} environment is like the {equation} or {equation*} environments and are used for arranging equations of multiple lines. (Use the asterisk to avoid automatic numbering of equations.) When you place an {align} environment inside $$, it is equivalent to nesting an equation environment inside another equation environment, hence the error message "Erroneous nesting of equation structures."

As you appear to have already discovered, simply remove the $$ surrounding the \begin{align}...\end{align}, and your markdown will set properly.

Other environments you may wish to explore are {multline} or {multline*} to left-align the first equation, and right-align the last equation, {gather} or {gather*} to write consecutive equations without alignment, {flalign} or {flalign*} that works like {align} but right-aligns what occurs after the ampersand, and {alignat} or {alignat*} that allows for several columns of equation to be aligned rather than just 2.

Related Solutions

[Tex/LaTex] Can’t generate png with Error: Erroneous nesting of equation structures

Don't use align inside equation. Use aligned instead. Also there is no need for varwidth. The standalone class provides that option itself.

\documentclass[border=5pt,varwidth]{standalone}
\usepackage{amsmath}
\begin{document}
\begin{equation*}
-\frac{\sqrt{2{{x}^{2}}-5x+2}}{3}\le x<0 \Leftrightarrow \left\{ \begin{aligned}
&   x<0  ,\\
&   -3x\le \sqrt{2{{x}^{2}}-5x+2}
\end{aligned} \right. \Leftrightarrow \left\{ \begin{aligned}
&   x<0  ,\\
&   9{{x}^{2}}\le 2{{x}^{2}}-5x+2
\end{aligned} \right. \Leftrightarrow \left\{ \begin{aligned}
&   x<0  ,\\
&   7{{x}^{2}}+5x-2\le 0
\end{aligned} \right. \Leftrightarrow
\end{equation*}
\end{document}

[Tex/LaTex] “Erroneous nesting of equation structures” message- I can’t see what’s wrong

You should not nest align in equation. The align environment is enough:

\documentclass[]{article}

\usepackage{amsmath}

\begin{document}

\begin{align}
\begin{split}
  a(t_{n+1}) \cos \varphi_{n+1} = a(t_{n}) \cos \varphi_{n} + \sqrt{2E_{n}}(t_{n+1} - t_{n}) \cos( \alpha_{n}+ \theta{_n}),
\\
b(t_{n+1})\sin \varphi_{n+1} \left(1+ \delta \sin^{2} \varphi_{n+1} \right) = b(t_{n})\sin \varphi_{n} \left(1+ \delta \sin^{2} \varphi_{n} \right) + \sqrt{2E_{n}}(t_{n+1}-t_{n}) \sin (\alpha_{n} + \theta_{n}),
 \\
 \theta_{n} + \alpha_{n} + \theta^{*}_{n+1} - \alpha_{n+1} = 0,
 \\
 \sqrt{2E_{n+1}}\cos \theta_{n+1} = \sqrt{2E_{n}}\cos\theta^{*}_{n+1},
 \\
 \sqrt{2E_{n+1}}\sin\theta_{n+1} = \sqrt{2E_{n}}\sin\theta^{*}_{n+1}-2u(\varphi_{n+1}, t_{n+1}).
\end{split}
\label{system}
\end{align}
\end{document}

This compiles (but looks terrible, imho).

With horizontal alignment it looks better I think:

\documentclass[]{article}

\usepackage{amsmath}
\usepackage[margin=1cm]{geometry}

\begin{document}
Without alignment:
\begin{align}
\begin{split}
  a(t_{n+1}) \cos \varphi_{n+1} = a(t_{n}) \cos \varphi_{n} + \sqrt{2E_{n}}(t_{n+1} - t_{n}) \cos( \alpha_{n}+ \theta{_n}),
\\
b(t_{n+1})\sin \varphi_{n+1} \left(1+ \delta \sin^{2} \varphi_{n+1} \right) = b(t_{n})\sin \varphi_{n} \left(1+ \delta \sin^{2} \varphi_{n} \right) + \sqrt{2E_{n}}(t_{n+1}-t_{n}) \sin (\alpha_{n} + \theta_{n}),
 \\
 \theta_{n} + \alpha_{n} + \theta^{*}_{n+1} - \alpha_{n+1} = 0,
 \\
 \sqrt{2E_{n+1}}\cos \theta_{n+1} = \sqrt{2E_{n}}\cos\theta^{*}_{n+1},
 \\
 \sqrt{2E_{n+1}}\sin\theta_{n+1} = \sqrt{2E_{n}}\sin\theta^{*}_{n+1}-2u(\varphi_{n+1}, t_{n+1}).
\end{split}
\label{system}
\end{align}

With alignment:
\begin{align}
\begin{split}
  a(t_{n+1}) \cos \varphi_{n+1} &= a(t_{n}) \cos \varphi_{n} + \sqrt{2E_{n}}(t_{n+1} - t_{n}) \cos( \alpha_{n}+ \theta{_n}),
\\
b(t_{n+1})\sin \varphi_{n+1} \left(1+ \delta \sin^{2} \varphi_{n+1} \right) &= b(t_{n})\sin \varphi_{n} \left(1+ \delta \sin^{2} \varphi_{n} \right) + \sqrt{2E_{n}}(t_{n+1}-t_{n}) \sin (\alpha_{n} + \theta_{n}),
 \\
 \theta_{n} + \alpha_{n} + \theta^{*}_{n+1} - \alpha_{n+1} &= 0,
 \\
 \sqrt{2E_{n+1}}\cos \theta_{n+1} &= \sqrt{2E_{n}}\cos\theta^{*}_{n+1},
 \\
 \sqrt{2E_{n+1}}\sin\theta_{n+1} &= \sqrt{2E_{n}}\sin\theta^{*}_{n+1}-2u(\varphi_{n+1}, t_{n+1}).
\end{split}
\label{system2}
\end{align}
\end{document}

Best Answer

Related Solutions

[Tex/LaTex] Can’t generate png with Error: Erroneous nesting of equation structures

[Tex/LaTex] “Erroneous nesting of equation structures” message- I can’t see what’s wrong

Related Question