How can I format Mathematica expressions for $\LaTeX$ without manual intervention? [closed]

Question

I want to show my work to my audience mathematically. My audience is not interested in Mathematica but in the math itself, so I want $\LaTeX$ output. I tried TeXForm, but my trial made this question look too complicated. How can I print my work easily with beautiful typesetting on A4-sized paper?

 AA = -a*g/(A*(2*g*h)^(1/2));
 aa = (F1 + F2)^2/(2*a^2*g);
 BB = 2/A;
 Du = F1 + F2 - 1.2;
 Dx = h - aa;
 ...
 Px = AA*Dx - BB*Du // Simplify;

---

The video here shows many ways but I haven't yet found one good way. Anyway they may help someone.

Different ways

Way 1

Export["/tmp/test.tex", { AA, aa, BB, Du, Dx, Px}];

Way 2

{ AA, aa, BB, Du, Dx, Px} // TeXForm;

Perhaps related

1. Breaking long equations in $\LaTeX$ here.

2. This question but in the TeX-biased form here, more about formatting and related.

Answer 1

One idea is to put everything in an align* environment.

SetAttributes[MassAlign, HoldAll];
SetAttributes[AlignElement, {HoldAll, Listable}];

AlignElement[elem_Symbol] := StringJoin[
  ToString@TeXForm@SymbolName@Unevaluated@elem,
  " &= ",
  ToString@TeXForm@elem,
  " \\\\\n"
 ];

MassAlign[list_] := StringJoin[
  "\\begin{align*}\n",
  AlignElement[list],
  "\\end{align*}"
];

Here it is applied to your example.

AA = -a*g/(A*(2*g*h)^(1/2));
aa = (F1 + F2)^2/(2*a^2*g);
BB = 2/A;
Du = F1 + F2 - 1.2;
Dx = h - aa;
Px = AA*Dx - BB*Du // Simplify;

MassAlign[{AA, aa, BB, Du, Dx, Px}]

\begin{align*}
\text{AA} &= -\frac{a g}{\sqrt{2} A \sqrt{g h}} \\
\text{aa} &= \frac{(\text{F1}+\text{F2})^2}{2 a^2 g} \\
\text{BB} &= \frac{2}{A} \\
\text{Du} &= \text{F1}+\text{F2}-1.2 \\
\text{Dx} &= h-\frac{(\text{F1}+\text{F2})^2}{2 a^2 g} \\
\text{Px} &= -\frac{\frac{\sqrt{2} a g \left(h-\frac{(\text{F1}+\text{F2})^2}{2 a^2 g}\right)}{\sqrt{g h}}+4. (\text{F1}+\text{F2}-1.2)}{2 A} \\
\end{align*}

Be careful, this is a String so you should copy it as Plain Text in Mathematica. In $\LaTeX$ it looks like

\begin{align*} \text{AA} &= -\frac{a g}{\sqrt{2} A \sqrt{g h}} \\ \text{aa} &= \frac{(\text{F1}+\text{F2})^2}{2 a^2 g} \\ \text{BB} &= \frac{2}{A} \\ \text{Du} &= \text{F1}+\text{F2}-1.2 \\ \text{Dx} &= h-\frac{(\text{F1}+\text{F2})^2}{2 a^2 g} \\ \text{Px} &= -\frac{\frac{\sqrt{2} a g \left(h-\frac{(\text{F1}+\text{F2})^2}{2 a^2 g}\right)}{\sqrt{g h}}+4. (\text{F1}+\text{F2}-1.2)}{2 A} \\ \end{align*}